I compared its sound quality against a Marantz MA500 and a Mackie 1400i . I actually preferred the sound of the AMP 5.1 over the other two in terms of sound quality, with the MA500 a close second followed by the Mackie. The comparisions were made using a DIY sub with 2 different drivers tested in the same enclosure. One of the sub drivers was a car audio Soundstream USA12 DVC which had 4 ohm voice coils wired in parallel. The MA500 would play it but not very loudly before shutting down, of course the mackie had no problems with the 2 ohm load either.
Fans get annoying after a while.
I give the 5.1's a value rating of 5 because you can't beat the price for what you get, and overall rating of 4 because I think there could have been atleast 1 more feature to them. Cooling fan runs continuous. There is not an auto on feature to turn amp on when a signal is received. Hook up was very easy. It works just fine for my center channel in my home theatre setup.