I've had my 1st ride on an 800 from King's Cross to Grantham and was glad to get off,one of the most uncomfortable journeys I've had (the worst was on GWR 800 which left me in pain on a trip from Bristol TM to Paddington),both trips in 1st class
The ride north out of King's Cross was extremely rough and I won't mention how uncomfortable I find any Fainsa seat
I was sat near the end,though how much difference this would make I'm not sure
I will take another longer trip to see if I was unlucky with the ride quality,but once the MK111 & Mk 1Vs have gone I will not be using LNER on my trips from Grantham to Edinburgh,I want to be able to walk at the end of the journey