There is good reason to loose sleep over it :)
Currently i have a set of 5B's and am pushing 120 watts of Denon power to them. Somethings telling me they want more...I think upgrading to a tower will make a big difference.
The more and more I listen to the 5B's the more I realize that they are definately less lively than the old 532's. The 532's seemed to produce more effortless flowing music.