Greg, I am using some M2's for front wides provided by audyssey dsx and it works fantastic it is a very noticeable improvement. I originally had just M2's and 2X8" subs and my QS4's and I got M80's and the difference was no where near what I was expecting. with that said I would not worry about going to M80's from M60's unless you have a really large room. I may try front height's at some point but I don't really believe it will add as much to the experience as front wides do. I look forward to hearing your feedback once you make the change.
