There are several other considerations. Are you looking for something that emphasizes CD level reproduction or does it have to do high-rez as well? The best sounding DACs for CD resolution playback are often CD only DACs,
Most DAC manufacturers focus on the digital side--DAC chipsets, clocking/re-clocking, exotic filter reconstruction of the signal, etc. But, there are other manufactures that employ "primitive" and simple digital to digital to analogue conversion and emphasize improvement in the analogue circuit. The two types of DACs can sound quite different, and it is worth your while to listen to both. While they measure quite poorly, Audio Note DACs, to me, sound fantastically natural, relaxed and beautiful. They represent quite the extreme in the emphasis in the analogue side. Some of their cheaper models (still not cheap) have essentially the same digital circuit as their crazy expensive top end DACs--the price difference reflecting the quite exotic exclusive parts they employ in the analogue side. Synthesis Audio and Lector, both Italian companies are other examples of analogue side DAC makers that make really nice sound stuff.
Because it is talked about so much, it is easy to get caught up in R2R, filter choices, etc., but, it is worth at least trying a different path. The result might surprise you.