The first of the sleek new generation of Caledonian Sleeper trains between Scotland and London rolled into Glasgow at 10.08am on Monday – two-and-three-quarters hours behind schedule and with passengers receiving full refunds.

The 140 passengers were the first to experience the historic journey which struggled to stay on the rails thanks to booking mix-ups, water leaks into cabins and a delayed driver.

The southbound service was also delayed, by signalling problems, which meant the first service into Euston arrived three hours late.

Facebook Twitter Pinterest The Caledonian Sleeper speeds through a station. Photograph: Jeff Holmes/REX/Shutterstock

Part-funded by a £60m grant from the Scottish government, the £100m-plus service, which launched a year behind schedule, includes double beds and ensuite showers in the most expensive cabins, accessed by hotel-style keycards.

Soon after departure from Euston on Sunday night it became clear that, at least on the Glasgow half of the 16-carriage train, many cabins were wrongly booked. Squeezing down coach K, where upper bunks were still locked away and appeared unable to be made up, the occupants were gathering uncertainly at the doors, with staff squeezing past cheerily promising to find a solution.

For Gavin Mair, 34, and his partner Jade Barrett, 30, it was not quite the restful evening they had been looking forward to: Mair had spent the morning running the London marathon, for the best part of five hours, and had been booked on the train as a treat by his father. Despite the Glasgow schoolteachers being short of a berth, Mair was impressed with the new surroundings: “This is pretty nice. My father referred to the train as the boneshaker, so this is a bonus.” Shortly afterwards they had to vacate their cabin when water started leaking in, apparently from an air-conditioning unit.

Elaine Howe, 59, a Glaswegian waiting for a bed to be found for her husband, was nonetheless impressed. A long-term occasional traveller on the sleeper, she said: “The old one was so dark and dingy – this is far superior. You couldn’t get wifi or sockets.” Her husband, Thomas, pointed out the plugs, USB sockets and new lights.

Jeff and Micki Colquhoun, retired financiers from Maine who were travelling to the Shetland music festival, had to be moved to another cabin after finding themselves separated by a dividing wall. They were eventually allocated a double – albeit without an ensuite bathroom. “It’s a bit chaotic, but everything new has teething problems,” said Micki. “It’s fun, beautiful, we love it.”

The sleeper operator Serco has abolished the possibility of sharing a room with a stranger – a change opposed by some solo travellers, who will now pay about £55 more a night to occupy a “classic room” with bunk beds. Those with slimmer budgets and the necessary fortitude can still book seats from £45, now with an overhead locker thrown in.

Facebook Twitter Pinterest Berths on the new Caledonian Sleeper complete with plugs and USB sockets. Photograph: CFH Photography

“Our research found that a lot of people didn’t sleep because of worries about security, so now they’ve got a locker,” said Magnus Conn, the operations director. At 11pm in the lounge car, the frazzled Conn admitted he had not slept for 38 hours.

The lounge car can cater for almost twice as many people, lured by the promise of meals rustled up in a new galley kitchen with three different ovens, a state-of-the-art coffee machine and a proper toaster, replacing the two microwaves that hitherto served the route.

Service remained sketchy – almost two hours elapsed before a bag of crisps arrived for the Americans. In a fortuitous teething problem, the Guardian’s order of a small, delicious game pie was accidentally delivered in triplicate.

At 3.55am, the train came to a halt at Newcastle. A combination of the East Coast diversion and a problem on the incoming Highlander service from Fort William had left the train without the driver to carry out the final leg of the journey. Crew gathered in the lounge car, unable to take a short cigarette break while stuck on a bridge over the Tyne. “We’re like zombies,” one smiled. “This is our lunchtime.”

Facebook Twitter Pinterest One of the top-end double-bed cabins. Photograph: CFH Photography

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Eventually, the train arrived in Edinburgh where Glasgow-bound passengers ate breakfast. The toaster was functioning perfectly – although the steward apologised for the absence of any butter. The Mairs-Barretts’ marathon was not yet done; the power on the train switched off immediately after they ordered breakfast, putting the coffee machine out of action.

Train staff, who remained remarkably cheerful and resilient throughout a shift extended by five hours, booked onward taxis for passengers who had missed connections – or in the Mair-Barretts case, the start of work.

All the passengers who spoke to the Guardian were, nonetheless, by and large delighted. The little things – such as butter, or a driver at Newcastle – will doubtless come. The Colquhouns, upgraded to a double, were enthused for their visit to Scotland: “It’s been a terrific start.”