I'll second this! I've been there a couple of times. Always pleased with their work and their service.
The first time I was there because I backed into a rock and it bent my rear down pipe on the rocks. The guy put my Jeep on the lift and we took a look at everything together. He looked underneath at it all the scars and the damage and said "well, I can see that you ACTUALLY use this thing. We need to hook you up with something. I'll do all new tubes, and tuck it up as far as I can, and I'll also use some heavy duty tube so hopefully it'll last longer then this stuff. It's a bit harder to work with, but it'll be worth it." The steel he used was for sure very thick.
So many years go by and I'm at JV and I tear the crap out of my muffler and I bent one of the tubes actually. So I go back, looks at what I did, and he says to me something like "You obviously don't want to spend a ton of money on an muffler if you're gonna just smash it again right? Lets go upstairs in the loft I've got a bunch of take offs that are still good, we'll find you something used, and I won't charge you a whole lot for it." We found a Flowmaster that worked and I've been using that for a few years now. After he's done putting it on, he comes inside and goes "Wow, the tube on your exhaust is SUPER SUPER thick, it's almost like roll cage! Did you do that? It's really hard to work with, and I can't believe you bent it!" I just laughed and said "Hey, you were the one who put it in along time ago, so it would actually hold up for a while. And it actually did for the way I drive and where I drive. I guess you don't remember me, or when you put that in!" He goes "No, not at all, I can't believe I did that, but hey, it seems to be working pretty well I guess if it's lasted this long!"