I bought mine at Champion. The sales experience was decent, but the service experience after has been a bit lacking (like, they never did get back to me on replacing my locking lugs, and their parts dept has dropped the ball on me a couple of times, etc). Most dealerships make me pretty furious though, so they rate a "not so bad" in my book
I originally tried to buy at Mossy and ended up walking out on them after spending a few frustrating hours there (and buying from Champion the next day). Don't know if that reflects on the whole place, or just the saleswoman I ended up with, but she basically just kept lying to me about available stock (colors/options) that they could get in, and then changing the story slightly as we went along, trying to con me into taking a car that wasn't really what I was asking for. I finally had to just tell her point blank to show me paperwork on a VIN that had exactly what I wanted and would be there within 2 days gauranteed, and she couldn't (after dragging me through half the financing process already, etc).
I've had good experiences with both Sterling McCall (on 59S) and Baker Jackson (on 290) when dealing with them for parts stuff. I'm inclined to favor them both over Champion at this point.