With the exception of Kirby, SSB was pretty balanced. I think Pikachu was nerfed a bit too much in SSB:M, but maybe that's just nostalgia playing into it (but really, that headbutt sucks). Not sure what you mean by bloated...Though I miss some of the levels in SSB, and there are a lot of levels that don't feel complete, or alluring. I replayed the Onnet level though. I really, really like it now, and I love the music (I want it :(). Hopefully they'll fix character balances that were in SSB:M though.
I like flat (non-moving) levels a lot, which is why the "final" level where you fight the hands is fun. Nowhere to run or hide. Just smash, smash, smash. :)