Are Kenyans getting good value for their money?
That's the overriding question being asked about the SGR.
"I was among a group of people who wrote a letter to the president [Uhuru Kenyatta], specifically with regards to the value for money proposition," political analyst Tom Mboya told RFI on Tuesday.
At a staggering cost of nearly four billion euros--almost entirely funded by China's Export Import bank-- just for the first phase linking the capital Nairobi to the port city Mombasa, there is reason to be concerned, reckons economist Aly-Khan Satchu.
"Morocco and Ethiopia both built similar railways and it didn't cost a fortune," he told RFI.
"There are grave concerns that the amount of debt has expanded considerably under the Kenyatta administration. But the issue I think is whether this is sustainable, will it generate enough of a return to pay the debt and pay the Chinese off over time."
The government says it is confident the railway will boost GDP by 1.5 percent and allow it to pay back Beijing within four years.
However, the extent of China's influence in Kenya has come under scrutiny.
Chinese role questioned
"There were a lot of questions raised at that time and even more recently," continues Mboya. "Were some of the contracting processes done according to the law? Many of these questions haven't really been answered."
There was no actual bidding process, which meant construction contracts went directly to Chinese contractors, fuelling concerns about corruption.
"A lot of these projects have a bad reputation," says Satchu. "They're used particularly for campaign financing and this is happening all over Africa not just Kenya."
Satchu argues that Kenya is right to push ahead with the SGR despite the controversy.
"It's sitting on a 20-billion market, if you consider that it's right next to the Indian Ocean. If it wants to take advantage of that, Kenya must have first class infrastructure to the sea and the market, therefore it was necessary."
But at what cost?
The railway has angered environmentalists, as it cuts through Nairobi's National Park: a key wildlife migration route.
"We are seeing a lot of issues with elephants being very confused and now being hit on the road," Salisha Chandra, a board member of Nairobi National Park, told RFI.
"The way the SGR has been built on these really high embankments has cut off their migratory route, so they actually haven't placed the corridors in the right places for these animals even if they said they did extensive research."
The Kenyan government conducted environmental impact assessments and promised to provide adequate corridors for wildlife crossings, so as not to disrupt the ecosystem there, but Chandra says the government has shown scant regard for the law in the past.
"We've been fighting to stop the SGR going through Nairobi National Park since September last year but recently the government changed the law preventing stop orders being issued against any infrastructure project."
On Tuesday the National Environment Tribunal reinstated that stop order, meaning the government will have to seek approval before starting the second phase of the SGR to the geothermal town of Naivasha.
Still, the fact that the governmet was able to deliver the project in a "timely manner" should be commended, says Mboya, who recalls that railways in Kenya have a difficult past.
The last major rail project built by former colonial power Britain in 1896 was dubbed the Lunatic Express. Lunatic because British workers were said to be terrorised and devoured by lions.
With just one month to go till presidential elections in August, the Kenyatta government is hoping its new railway will be a key selling point, and less dramatic.