Picked up an NV425 last night from a fellow Bay Area TB'er and A/B'ed it with my SVT810E at practice. Ran my BEAD-tuned T-40 > SVT II Pro > cabs. While the Berg moves considerably less air, it's much more articulate and less boomy. It doesn't "feel" as loud as the Ampeg, but it "sounds" as loud, and sounds better. There's nuance now where before there was simply thud. I was worried that I would be too "hi-fi" and modern-sounding, which would be WRONG for my sludgey metal band, but it's not. It's just loud and clear! And man, it's an absolute dream to move around -- I was actually able to carry it down 2 flights of stairs all by myself! I'm pretty happy with the purchase!