On the No 38, passengers giving their verdict on the "Boris bus" might be discussing the man behind it, Mayor Boris Johnson, elected on precious few promises other than to rid London of his predecessor's "bendy buses".
"It doesn't make sense," claims one commuter of the new fleet of red London buses. Another counters: "It's a nice upgrade - and it makes you a little bit happier when you see the new, shiny one coming along."
Prototypes have run in London since 2012, but now the New Bus for London is to flood the No 24 route from Hampstead in north London, through Trafalgar Square to Pimlico, near Parliament - the first full service.
The 28 buses are the first of 600 to be delivered over three years - the culmination of Johnson's rallying cry in 2007. As a putative Conservative challenger to Ken Livingstone, the then-mayor, he tapped into nostalgia for the Routemaster double-decker, with an open door at the rear - for his first policy of note.
Critics say the new bus has a hefty price tag and high running costs. They question the wisdom of the open rear entrance, the platform that became emblematic of fun, leaping Boris versus dour Ken, worried about access for all. And they question the environmental credentials of the bus heralded as the greenest yet.
The first No 24 out of Pimlico garage at 6am tomorrow will be driven by Sir Peter Hendy, London's transport commissioner, and Leon Daniels, head of surface transport at TfL [Transport for London]. "It's fabulous," said Hendy. "It's a lovely vehicle, very comfortable, popular - everyone likes it. They love it."
The new bus retains the Routemaster's curves and its rear platform - open only when a conductor is aboard in the daytime. There are three doorways and two staircases, allowing for rapid boarding and access for wheelchairs and pushchairs.
Initial fuel consumption and emissions have not been as impressive as expected. But Daniels insists that results from the few new buses on route 38 will not accurately reflect what the bus will be able to achieve when the fleet is fully operational. "In any event, it's the cleanest and most compliant bus we have," he said.
Whatever the economics, it's hard to escape the main reason for the buses: the open platform and all it symbolised. As Johnson puts it, the ability to "hop on, hop off - fall over, should fate intervene in that way".
Livingstone happily admits having once enjoyed jumping on and off moving Routemasters, but getting older changed his view. He thinks Johnson missed a chance to bring in something that would have really tackled pollution: electric buses. "If I'd won I'd have ordered 9,000."