Past and present peer across the water at each other in this small West African state, one of several hailed by economists as flag bearers of a new rising Africa seen as a pole of investment and potential prosperity in a troubled, recession-hit world.

In New York, London and Johannesburg, fund managers, bankers and frontier market analysts are telling clients Sub-Saharan Africa, dismissed a decade ago as hopeless and chaotic, is now ready to rival India and China as an economic success story.

"People are pouring capital into the continent," said Charles Robertson, Global Chief Economist at investment bank Renaissance Capital. "We believe now is Africa's moment."

He cites figures to show that swelling growth and investment is buoying oil development, mining, banking, telecommunications and retail markets in the world's least developed region.

But bubbling up with the statistics are enduring questions about governance, poverty, stability, corruption, climate change and, crucially, if and how the extracted wealth will be shared.

At a launch by Renaissance in a Johannesburg hotel last month of a book Africa's "Economic Revolution", participants heard a prediction that the region's economy will grow from $2 trillion today to $29 trillion by 2050, greater than the output of both the United States and the eurozone.

The chic hotel of the book launch is a world away from Sangbulima, a hamlet of 1,000 souls perched on Tasso Island in the Sierra Leone River where wooden canoes loaded with nets cluster on a muddy beach not far from Bunce Island slave fort.

Across the channel is the iron ore loading terminal run by London AIM-listed firm African Minerals (AMIq.L), a major player in the Sierra Leone mining revival the government believes will propel the nation into a new promised era of African prosperity.

Day and night, Sangbulima villagers see the ore ships go by on their way downriver to the Atlantic Ocean.

"We see them pass," said Idrissa Kargbo, 38, "This mining brings a lot of money to the country"

"But, for us here, we are not seeing the money," he added.

Here, as elsewhere on this booming but turbulent continent, extractive industries, construction, mobile phones and other harbingers of modernity are thrusting themselves into the lives of Africans, stirring high expectations but also uncertainties.

AFRICA: AN UPLIFTING OR A "LOOTING"

Renaissance Capital, one of Sub-Saharan Africa's biggest cheerleaders, sees it "charging forward on almost every metric".

A chorus of similar reports from institutions, banks and consultancies forecasts Africa roaring ahead as a fast-growth pole in the next decade, its projected 5-6 percent expansion rate outstripping the expected global average by several points.

This upbeat outlook is pinned on an expected "demographic dividend" of a young and rapidly growing workforce in the next few years, on rapid urbanisation, and a surge in middle class consumers.

Around 90 million African households had joined the world's consuming classes by 2011, and this would rise to 128 million in 2020, according to a report by the McKinsey Global Institute.

The African Development Bank sees African consumer spending almost doubling in the next decade.

This is seen opening up huge investment and business opportunities, especially in retail, telecoms and banking.

But some are cautious about the blizzard of upbeat figures. "It clouds a lot of issues," Dianna Games, CEO of Johannesburg-based consulting company Africa@Work, told Reuters.

While acknowledging the "rising tide effect" of the African resurgence, Games believes the statistics conceal "shaky pillars" - especially failures by African governments to translate resource-driven growth into real improvements in education, health, jobs and a better business climate.

"There is so much that still needs to be done, policywise,' she said.

Ideological critics of 'Africa Rising' see a continent being not lifted but "looted". They say foreign corporations allied with local elites are applying a neo-liberal formula of resource-driven development that depletes and degrades Africa's non-renewable natural wealth, resulting in net loss, not gain.

"It's a kind of reheated neo-colonialism, a generalised resource curse," said Patrick Bond, Director of the University of KwaZulu-Natal's Centre for Civil Society.

In Sierra Leone, if new investments are to bring new jobs, some say they are still waiting to see them.

Sangbulima's residents say the nearby ore loading facility has employed only four people so far in their village. Their expectations may be unrealistically high as they live more than 100 miles (160 km) south of African Minerals's Tonkolili mine.

The company says its iron ore project has overall created many jobs for Sierra Leoneans, 9,000 to date.

But the Sangbulima villagers say their fishing livelihood has been disrupted by the throbbing engines and booming klaxons of the ore ships and the new channel markers studding the river.

"Two years ago, you would have seen smoke here, smoking the fish," said Idrissa, sitting with other villagers in a 'palaver' meeting with visitors under the shade of trees.

"The fishing career has been blocked now," he said.

An African Minerals spokesman said the company recognised it had a "unique responsibility" in Sierra Leone given the importance of its iron ore project to the local economy.

"From Q2 next year, African Minerals expects to be producing 20 Mtpa (million tons per annum) of iron ore, making it one of the largest producers in West Africa. This will generate significant revenue for the country," he said, without specifying how much. Local expectations are high.

"The only way to look at it, Africa Rising, is to look at how does it really benefit the African," said John Sisay, the Sierra Leonean chief executive of Sierra Rutile, another mining company in the West African country.

"Otherwise, what's the point?" he asks with a shrug.

DEMOCRACY HOPES, POLITICAL RISK

With its galloping growth rate of an estimated 21 percent this year, driven by the new iron ore projects, Sierra Leone has joined the pack of the bounding "African lions" - among the fastest growing economies in the world.

But Sierra Leone's prospects may look considerably sleeker from Johannesburg or London than from the pot-holed streets of Freetown, where services like power, transport and Internet are often obtained with difficulty - by those who can afford them.

Huge development challenges remain in this Atlantic state whose coastal mountains spied by a Portuguese explorer gave it its name of "Lion Mountain" and where white foreigners are still greeted with shouts of "Oporto, oporto" in the Temne language.

In 2007, it ranked last in the U.N. Human Development Index and still languishes among the bottom 10 on the list. Some 70 percent of its 5.5 million people live below the poverty line.

During its 1991-2002 civil war, Sierra Leone was a horrific poster-child of Africa's "Hopeless Continent" image, with its diamond riches driving a fratricidal conflict made notorious by documented amputations of limbs and rapes.

But, after a decade of peace, the country has emerged from those dark days, and Sierra Leoneans are not looking back. "We don't want that again," said ex-soldier Ibrahim Sesay, 64, after voting last month in the nation's third elections since the war.

Diplomats and election observers hailed the November 17 vote which re-elected President Ernest Bai Koroma as marking the graduation of a recovering failing state to a developing nation.

Senegal and Ghana have also held close but successful elections this year, part of a consolidating trend of democracy in Africa which economists like Robertson say has been bolstered by economic reforms and improved financial management.

But political risk still looms large. Democratic Republic of Congo remains a morass of instability and violence, the world fears a Jihadist state in Islamist rebel-occupied northern Mali and the unchecked Boko Haram insurgency in Nigeria is tingeing with blood that nation's widely hailed economic dynamism.

South Africa, the continent's largest economy, is struggling with sluggish growth and suffered violent labour unrest in its mines this year that embarrassed the ANC government and raised fears about potentially explosive post-apartheid inequalities.

"SOMETHING IS AMISS"

There are economic risks too. Sierra Leone's economy is so firmly harnessed to the chariot of the foreign-operated iron ore projects that when the biggest of these had start-up problems this cut projected GDP growth by more than half.

The IMF last year forecast 2012 GDP growth of 51 percent - one of the highest in the world - based on the commencement of iron ore exports from Sierra Leone by two mining companies, African Minerals and London Mining (LOND.L).

Citing start-up problems at the largest mining operation, African Minerals' Tonkolili and a weakening of world iron prices, the Fund slashed this projection to a more modest but still sizzling 21 percent GDP growth for this year.

African Minerals has cut its ore shipment forecast from Sierra Leone several times this year, most recently this month.

"For iron ore to be the 'hope of the nation' is a concern," said Aminata Kelley-Lamin, of the Network Movement for Justice and Development NMJD.L, an NGO which seeks to promote good governance and transparency in Sierra Leone.

Games says many African economies are too dependent on aid or volatile commodities and so vulnerable to outside shocks. "In Malawi, if the aid pulls out, it comes to a standstill. In Angola, if oil prices drop, it comes to a standstill".

Kelley-Lamin's NGO, local journalists and even some foreign diplomats question the speed with which the iron ore mining leases were passed by Sierra Leone's parliament in 2010, saying this process should be probed for possible irregularities.

"For the two agreements, it was like they passed under a certificate of emergency, there was very little scrutiny," said Kelley-Lamin. "Something was amiss," she added.

Government officials deny any secrecy, irregularity or corruption. "As far as I know, absolutely no bribes were paid to anybody," a spokesman for President Koroma, Unisa Sesay, said.

London Mining said it was operating with "integrity and transparency" and had followed all necessary and legal process. "Any suggestion to the contrary is entirely without merit," it said in a statement responding to Reuters questions.

African Minerals did not respond to specific questions about the lease approval process.

Some Sierra Leoneans are sceptical about just how widely the benefits from the mining deals will spread to the population.

"The deals are not for us ... They should review all these deals. If you want to mine our resources, build roads, schools, hospitals," said, Isatu, a businesswoman in her 30s who runs a Freetown clothing boutique and would only give her first name.

"Africa is rising for the political elite and for the investors, ... maybe we are in another phase of the scramble for Africa's wealth," said NMJD's Kelley-Lamin.

Whatever the future holds, Africa@Work's CEO Games said investors were looking for a deeper read of Africa's reality than just upwardly charging statistical charts and metrics.

"People want the nuances now. You can't operate on statistics, you want the details," she said. (Additional reporting by Tom Miles in Geneva; editing by Philippa Fletcher)

• A Permanent Economic Emergency