I owned an A23 and have had a couple of Emotiva amps - the XPA5, which I still have for surround sound duty in my 2nd system and a pair of XPA-100 Gen 2 monoblocks. They were decent amps, but nothing to get excited about. The top end of the A23 was a little bright for my taste and it's not going to control the bass with an iron fist, but one person's bright might be another's "detailed". The Emotivas are decent, but lack some of the detail of the Parasound.
If I had to pick one, it would be the Parasound, however my advice would be to save a little more and check out a Wyred 4 Sound ST-500 MKII (or find one used for about what you're planning to spend). It will have more detail, be a little smoother, and give you more "slam".