TC, you are right, I hate everything that runs with SWT. I forgot to include that. There's more hated stuff, but to make a list would take until The Second Coming, hence my omission to add it all. Plus I was rushing the post out a bit.
Put simply, the only things I like are the following, the rest has either a dislike status (ie, I'll put up with them if I have to, or whether avoiding them means missing a diversion over a rare line) or a hated status (ie, avoid at all costs, unless there is nothing else on the route (eg, the Alton route only gets 450s now it seems, but I need to FC the route, so I'll do it then)):
HSTs
158s
323s
That's all I like. Everything else has some negative thing about it. I will say I found plenty of legroom on the airline seats on the 390s mind, and the at-seat radio things worked for the vast majority of the time, essential for a long trip on a 390 (Crewe to Carlisle having taken around 2 hours and 20 minutes when I did it).
Sprinter, if you like 66s, try putting up with someone repeating that noise on their cam several times when you're extremely tired. Trust me, the ying-ying noise gets very irritable. So much so I was glad I wasn't going on that unit to NCL with the rest of the group...