Well...well...well, that's the million dollar question I'm trying to answer too.
I'm in the process of going with "In Wall" speakers after having floor speakers for MANY MANY years... My previous system consisted of Klipsch Forte's and KV 3 (center channel) speakers with a small pair of Boston Acoustic's acting as rear speakers..... The sound field in my old system was awesome, with great imaging. Anyway, we're building a new home now, my system no longer fits my wife's, errrh I mean our, new decor. Anyway, I had to get something with a higher WAF.
Therefore, I decided to go with "In Wall" speakers, check out my signature to see my new equipment. My old home sold faster than my new home could be built, so now I'm temporarily living in an apartment. I sold most of my old equipment on ebay (Klipsch speakers, Adcom Amp, and Yamaha Pre). Now all of my new equipment is packed in boxes sitting in a corner, including the plasma. Right now, I can't honestly say how my new setup with "in wall" speakers sounds. Since I've already swallowed both hook, line & sinker, I'm hoping that everything will sound okay.... actually I hope it sounds better than okay, I want it to sound GREAT!!!
Once we move and I get everthing installed, I will do a write up on how it sounds.... In the mean time, I'll keep checking your thread to see what other people are saying...

Just in case, I need to go back to the negotating table with the Mrs.....