Hi, I can only compare my current BAT Vk-500 (with BAT pack) to a Classe DR25 I used to own (both at 250 wpc). Each were an upgrade for me from my previous amps, and both were/are run balanced. The BAT is dead quiet, if there is any noise, it is on the recording. Midrange is very nice for SS, and bass is deep and tight. The high end is smooth, with maybe a touch less energy than some amps (which is fine with me). The Classe' was also smooth at the high end but maybe just the slightest touch "high-fi" sounding compared to the BAT. The BAT has an accuracy of timbre that, with good software, can make it sound (almost) like real instruments and real singers, playing music in my room. I am sure the BAT can be bettered and there are links on this forum that discuss other's opinions of which amps do just that. However, improvements are often system dependent and, in my system, the BAT was hands down better than the Classe. A final consideration, if your speakers are power hungry, and depending on the music you listen to, you might find the extra watts provided by the CA400 vs. the Vk-500 (400wpc vs. 250 wpc) to be the deciding factor. Let us know what you decide and what you think about your choice. - Tim