I used to have the DCD1500AE and always regretted selling it (and the matching amp), but I couldn't possibly make any meaningful comparison between that and the 720AE I have now because too much time has elapsed. All I can tell you is that the DCD720AE is a stunning player and I use it in preference to a Roksan Kandy K2 CDS. The 1510AE would have to be pretty jaw dropping to make the very significant price difference worthwhile IMO. Having said that, if I could afford to I would buy the new PMA1520AE and DCD1520AE in a heartbeat, due to the performance of the amp and the overall feel of a 1500 series set-up. I love Denon kit. Lovely design, a pleasure to use, and superb sound quality.