The issue, once again, isn't that the seats are hard (though the ones on S stock and 345s aren't, so that proves that one untrue). It's the shape of them which is unnatural for tall people due to a bodge to half fix the headrest issue that was flagged at mockup stage, presumably because they signed the contracts for the seats too early and couldn't change them once it was found that they had a major fault in the design.
I don't think I would switch to bus, it could be worked around by e.g. sitting sideways across two seats with back against the window as I have to on other units designed badly for tall people like 153s, but for all the shouting about these things being amazing they really are quite, well, average.
Level boarding is certainly a killer app, as it were, but I'm not saying they shouldn't have gone with Stadler, the issues are almost entirely with matters that Stadler will quite happily change for you (and equally you can fit the stuff like the screens on any unit - though I think the Class 700 PIS is hugely better - and pretty much all regional stock is now "walk through"). It's Merseyrail who have designed an utterly mediocre interior.
I would certainly say TfW and Greater Anglia have got the interiors far closer to right.