I am currently playing a Warwick Thumb BO 4 into a GK 400RB (series 1 or 2) through a pair of Peavey 410TX cabs. I really like the sound I'm getting out of this setup, but, I'm looking for more power/headroom as I'm running the 400 at almost 3/4 volume. So, I've been looking at either the rb-1001 (current series (700w) or the MB800 (800w), there is more flexibility in tones in the RB, but the MB has more power... Cost is not a factor as they are relatively close in price. Durability is a factor though. What do you guys thing about both amps and what would be the recommendations?