As noted in an earlier comment of mine, I have one (actually made for burning weeds) connected to my gas grill tank, and a fancy Japanese one inside. They're honestly pretty rinky-dink. What they are good at is transferring heat just to the crust. But they only do a small patch at a time, and you have to hover for far longer than you'd think. Like, you do a little patch, leave the torch there for 30 seconds, move on. They just don't pump enough energy into the crust fast enough for them to be a general solution. I use them for touching things up, or crisping up a bit.