can anyone give me a comparison to these two amps? -how much more headroom/volume does the 400+ have over the buster? -are the preamps similar in the two amps, or is the buster's pre voiced differently than the 400+? -what does the buster head weigh? i have a 400+ right now, which the master volume never goes above 3 on, so i think i may be able to get by with less power. i've always loved the head configuration of the buster but was worried they wouldn't have the volume i'd need.