I actually think the experiance is pretty much the same as it was 20 years ago on board (economy), as said by others, its the airport experiance that has got worse, although the introduction of the "print at home" boarding pass has at least cut the check in queue out of the experiance.
I have to say that personally USA airport security is by far the worst bit about the journey now - it is getting to the point where you think about travelling in just a thong (and trust me - I dont look good in a thong!) to avoid the taking off of belts, shoes, coats, etc.
Personally I would be quite happy to walk through one of those "full bodied x ray things" where the operator can see you naked, if it avoided all the security hassles...