I too am upgrading from a polk system. The LSIs just didn't cut it for me. Paradigm, b&w, def tech, revel, psb, dynaudio, and thiel are the brands I auditioned (Along with McIntosh and Wilson which I can't afford). I'm going to post a write up on my impressions of each brand tomorrow evening (going back for a final listen of my top three and then pulling the trigger).
My price range was 5k to 10k, but After listening to the Paradigm S8s, and B&W 803Ds I decided I was willing to go up to 12 (5 speaker system). I did listen to some killer systems for around 5! Tomorrow night look for my post if you're interested, again it will reflect only my opinion. To be honest I would be happy with any of the brands I listed.