My wife (a mobility scooter user) and I went to look at the HS2 mock-ups in Derby and unfortunately found the accessibility a little bit disappointing, despite assurances from the staff that it had been thoroughly tried out with disabled user groups.
Level boarding will only be available at HS2 dedicated stations, with a manual ramp still required anywhere on the 'classic' lines.
Anyone boarding in a wheelchair or mobility scooter via the door on the 'wrong' side has to do an immediate sharp 120 degree turn to do a dog-leg around the accessible toilet, or do a three point turn in the vestibule area. This is exactly the same problem as Voyagers have and makes boarding them with a mobility scooter extremely challenging.
The 'accessible' spaces are up against a solid partition, so difficult to manoeuvre a mobility scooter or chair without rotating rear wheels in and out, and not enough space to turn a scooter around completely. There is at least a flip-up table to give a bit more manoeuvring room, but it's still tight.
There is no direct access from the disabled seats in Standard class to the buffet/catering area.
The bike storage area has no provision for tricycles or other disabled-adapted cycles, though this was probably too much to hope for on any train.
Also, the demonstration 'buggy' area only had space for 1, or maybe 2, very small buggies. Not exactly ample provision.
Although this probably all complies with the appropriate legislation, and is what the government ordered, it's disappointing that the opportunity hasn't been taken to make this a 'best in class' experience for allowing people with disabilities to travel comfortably and independently, especially with an ageing population.
It's not like something much better isn't possible, as Stadler have shown with their units on Greater Anglia.