There is a lot of info on the M3 here and in other reviews online. It was a Stereophile Class A component if you care about that. I happen to like mine and I have owned equipment from BAT, Rogue, Rotel's top of the line, W4S, Nuforce, and Parasound JC1 amps to compare to. Revel, PSB, Usher, and Acoustic Zen speakers as references. The M3 is good but it is mostly about synergy with your other equipment and room, and your ears and sound preferences. I used my M3's bass management feature with Usher BE-718 monitors and a pair of JL Audio F110 subs and it worked great. Now I'm running it full range with Acoustic Zen Adagios because they don't need the protection of a limited bass signal. The NAD is smooth and rounded off at the extremes a bit and that is one of the things I like about it plus it is fat in the middle. It still has detail and good soundstage width and depth. It matches well with my Adagios and it did with the Ushers, too. I'm not familiar with Tetras (except for the freshwater tropical fish-I have a bunch of them) so read whatever you can and take your chances if your research sends you in that direction.