Parasound A23+ or used Parasound A21

I really like the synergism of the Denafrips Ares II, Parasound A23, and B&W 705 S2.  The 705s can be a bit harsh on some recordings and the A23 seems to tone them down a touch.  I like that.

I have not heard the  A23+.  I'm sure it would be an upgrade but I'm not sure the extra power of the A21 would not be as good, or better.  The price would be in the same ballpark.

I listen to the likes of Pink Floyd, Bob Segar, and Dire Straits at a pretty high volume in a small room.

I would like any opinions.  For instance, is the A23+ a great improvement over the A23?