Kinda late, but I bought a rev jr pro 20w a month ago and I can tell you it's LOUD!
I live in Norway, and unfortunately for us, the only Krank dealer in our country doesn't sell Kranks anymore. I had to buy mine without testing one. The one thing that I was worried about too was the bottom-end. I bought the head and the 1x12 closed cab. Its so loud your ears will get torn off by the shear sonic power. Ok, maybe not that loud but you get the picture =) Tested it with my friends ENGL cab (4x12) and it was right up there competing with his Screamer 50.
I'm very happy with it. Also the sweep control will let you adjust the focus of the EQ so you can make the amp work with pretty much any guitar and/or cab. Never tested it live since I cant play with my band for another year, but I would definitely gig with it. Its just awsome =) Yeah, and like always, none of the vidoes around does the amp justice. Hope this helps.