the charter spec 757 is one of the worst aircraft ever for leg room.
I myself have fallen victim to a 5-6 hours flight, with appalling leg room, and so I know exactly how you feel. That said, having been on Jet2's 757's before, (with the charter-style seats) and after the slimline recaro seats were rolled out, I can definitely speak of the huge difference in legroom you get with the slimline seats - even for someone 6ft+.
Not sure why anything smaller than a 757 is unsuitable for New York
What I meant was anything smaller than a 757 would be unsuitable
for Jet2, simply because of how increasingly popular the seasonal flights are. By reducing the capacity available, Jet2 wouldn't be able to sell as many seats, and might have to put on extra sectors. I understand how Norwegian plan to do USA with the 737MAX, but I beleive that NAX's business model is a little less seasonal than Jet2's, and from what I understand, the flights will be more frequent than just seasonal. If Jet2 were to have more frequent flights to the USA, I do think that the 737MAX would be a viable option, but just don't quite think the NG is up to it, as you said
