Can't comment on the Sony, but I owned the AA Prima II.
Sound was refined, relaxed and lovely, but still lots of grunt, speed and detail. My bias is towards tubed players for their warmth, refinement and ease, and overall the way they tend to ameliorate digititus better than SS...at least at this price point.
Similar sound to the other tubed players I own: Cary 308t and Metronome CD2v Sig. So if you know these, you know the AA Prima. All so similar to me in their analog like delivery, that it was difficult to choose the sell victim. I decided to sell the Prima mainly because the tubes were soldered into the socket. Who needs that hassle when it's time to replace them?
Don't know that you will get one for $500. I see version 2 in the 600 to 700 range. Version 3 is around $1000 to $1200.
Good luck!