charles1dad, interesting that you referenced dlcockrum yet were mute with regard to teeshot's more relative post.
The extra power beyond the minimum recommended would only be needed to provide higher dB output for a given room size. In that sensitivity decreases (and increases) proportionally with impedance in speakers such as the Thiels it's prudent to be mindful of actual power output in the given circumstances.
In the case of a speaker with extended bass output such as the CS5's it might be fair to assume that that room size wouldn't be all that small to begin with.
If everything is performing as it should be, and depending on the desired volume output in the given room size, other than increased dynamic range, decreased potential for distortion and clipping and with that, less likelihood of speaker driver damage; there is no reason to expect the higher power amp to necessarily sound better, or visa versa .