I'm not very familiar with godsmack but I have to say, the Schmidt is capable of an AWFUL LOT. It has a very decent amount of gain on tap. I have never once felt I needed 'more' out of it. I believe it comes down to your pickups. I've run a number of pickups through it (including EMGs) and it has delivered considerable chunk. It's no vh4 but it's no slouch, by ANY means.
In saying all of this, you may find an Einstein 50 a better fit.