Completely forgot about my own thread.
Yes, different woods can impart different flavors into the meat. Personally I love cherry wood, although cherry is more expensive, and harder to find. My wife has a weird reaction to mesquite, so I don't use that, although I do like mesquite flavor. Apple is another really good wood, and is easier to find. Nothing wrong with hickory, though.
I use baby backs, because one, they fit on my smoker without having to cut into segments, and two, they're less fatty than St Louis or spare ribs (although I will do those, as well, since they're cheaper cuts). I also keep water in my chip pan (have to top it off periodically during a smoke), which helps cut down on the dryness.