zilch0md: from diagram you posted above: for 10V and 20kHz you need at least ~2.5V/us to keep rough shape (good looking on scope) of sine-wave. But you need much more (e.g. ten times more) to keep THD low.
1KV/us is useless if you ask me, but there are many other things that matters more than SR.
In amp that I designed I am using LT1122 (60V/us) which are better than LT1363 in my opinion. Even LT1115 (only 10V/us) sounds great (still better than LT1363 for me). The other amp - electrostatic one - I designed (not using OA) is quite slow (only 25V/us) and still sounds lovely.
So I don't think there is correlation between very high SR and "good sound".