I've been trying to learn about the relation between the power rating and the brand/overall quality. It seems that after all wattage isn't everything, which makes it harder for me. One simple way to put it is asking you which one would you chose. These are some amps that I've been looking at: Trace Elliot GP7 SM 130 GK RB-400 III Hartke HA 3500/7000 GK RB-400 IV (In terms of price, assume that only the GK IV is a bit more expensive than the others) I play mostly rock (from soft blues to hard rock). If you could specify why would you choose that one, I'd appreciate it Thanks guys!