I've been using a pair of 112s (Avatars) for low tuned Metal for the last three years. I used them for gigs where load in/out is a little more difficult (long flights of stairs, snowstorm, laziness etc).
With a a P.A. assisted show, they'll give you all the stage monitoring you'll ever need, even with screaming Soldanos and Mesas flanking you, lol. Minus the P.A., they'll get the job done but they'll be working pretty hard. Funny thing, though - when I was using a 650w solid state amp, I had to trim the bass on my head's eq pretty significantly to avoid bottoming out on the low B. When I paired them with a 225w tube head, they were the loudest and lowest that I ever heard them. At a show last fall, the power to the P.A. went out so it was all backline and vocal P.A. for the rest of the night. I was initially terrified of having to crank it but my fears disappeared soon after.
I'm still switching up to a pair of 15s, though