The Thiels need the current to drive them at demanding low impedances (3 Ohm minimum) so that the low and lo-mids will come through with punch. The W5 is a great amp and should be able to provide all the cureent needed. I used to have the CS7s driven by Bryston 7BSTs and while the sound was good, there were time when I felt they also bright.
After a (long story) selling the CS7s and the Brystons, I am now back with Thiels again, this time with Cs6s. But now I am driving them with a Krell 400cx amp and I have all the warmth, punch and sweetness I could ever want. I would recommend cj, ARC, Levinson, Theta, Rowland as other alternatives. If possible, home audition the Classe amps before you buy, if that is still your interest. My guess is that the Classes will not be any "warmer" than the Simaudio you now own. Let us know what you do though. I am always interested in hearing about what other Thiel owners are up to.
After a (long story) selling the CS7s and the Brystons, I am now back with Thiels again, this time with Cs6s. But now I am driving them with a Krell 400cx amp and I have all the warmth, punch and sweetness I could ever want. I would recommend cj, ARC, Levinson, Theta, Rowland as other alternatives. If possible, home audition the Classe amps before you buy, if that is still your interest. My guess is that the Classes will not be any "warmer" than the Simaudio you now own. Let us know what you do though. I am always interested in hearing about what other Thiel owners are up to.