What's been lost in this discussion is that the 737 is based on the 1958-era 707 in it's major configuration -- with its circular fuselage it is not built with compatibility with the human body in mind so of course you are going to feel like flying is hell after a transcontinental trip on what was originally intended as a regional jet.
Even if you survive the flight on a 737 you are going feel like you're dead. Since the 737 and A330 represent the vast bulk of planes built, anyone concerned about the environmental impacts of air travel (e.g. climate change, noise) would want to see the 737 get a clean sheet design like the 787.