Well, I have the Parasound A23 (obviously a model below the A21) and the stereo version of the M700 (the S300). I find the S300 is superior in every regard - not in a really significant way, but clearly audible. Cleaner and more articulate, the A23 sounds “thick” and less resolving in comparison.
I’m guessing a similar difference would be heard between the A21 and the M700s.
My $.02.
I’m guessing a similar difference would be heard between the A21 and the M700s.
My $.02.