It can but overdriving the gain sounds pretty much the same as pushing your speakers past xmax. And yeah, maybe not quite doubles the wattage but close to it in most amps. But most cabs can't take much more than 600w anyway so it's not necessary unless you use a really big cab IMHO. And if you use two cabs, you'll want to run each side separately. Bridging is more for those who have stereo amps with less power. 600w should be plenty for anyone. Cliff Williams did AC/DC with two SVT's, which are 600w total. Oh sure, he's using 4 Pros now, but back in the day, that was considered huge.