I have both and as amplifiers and to me they sound more alike than different. After a couple weeks of listening/comparing, the 2160 sounds cleaner and more balanced, the 2150 warmer but this is very slight, not something that would cause me to purchase the newer unit unless you wanted the better dacs and additional features of the 2160. I don't listen at ear-bleeding levels or in a big room so can't say I hear much difference in dynamics or power.