The 610 gets muddy stacking male voices? How often do you stack track after track of male vocalists? That's just funny. Generally when people say they're looking for a vocal preamp--it's for lead vocals. Which, if you're staking those, you NEED a bigger sounding mic/pre.
Also, I think it's misleading to say it distorts easily with the pad engaged. Counting the pad, there's -25db of attentuation available on the first gain stage. Even more if you've got a pad on the mic. What in the heck kinda mic you using that fuzzing out the first stage with -25db? Not that I've had to take it that low, but...
Also...pop/rock lead vocals=often "distorted"...though currently with more of a Neve'ish sizzle fuzz than tube break up, but...it's like claiming that Marshalls suck because when you put a sine wave through them with the gain on 7 it "distorts", and then using your Boogies...different break up-but, forest for the trees, not so different conceptually.
BTW...Guitar Center has the Brick/GT55 combo for $499 now...you can't argue with the deal that is...the Brick was a $400 pre until last week.