I've found that in general the "hardest " levels are the easiest and vice versa. I suppose that this is because you are a) more cautious, and b) you can deal out more damage. Now, that said, I beat the game on Padawan level and am currently playing it on Jedi. The only real difference that I've seen is that the enemies seem to be able to aim better, but all of the levels I hated on Padawan still suck (ie Artus Topside and Nar Shadaa). I figure though that that's more a function of the type of enemies, etc. I'd much rather fight stormies than aliens. I just got through NS with better health on Jedi level than I did on Padawan, so I think that while Padawan has less enemies, that it's really harder. One other example from Dark Forces: I found that Medium difficulty was the hardest for some reason.
Duct Tape is like the Force: it has Light Side and a Dark Side and it binds the galaxy together.