I have a preloop 1987x Black Sun. Amp Chugs more than any boosted amp I have had (5153, SLO, Diezel Vh2, XXX, Avenger). It's really fun to play. It has a lot of gain and if you crank up the volume, you really need to tighten up your playing. Thing is like holding a bolt of lightning. And when I say it chuggs, it is insane. I use a ts as a boost for low tunings just to eq more treble in there without the fizz when I want high end notes to ring out. But when I am palm muting, i click it off, because this thing does not need a boost to tighten up. The best thing about it for metal, is that you can have that tight of a sound with that much bass, even in E standard.