This amp is extremely reliable. I not only would gig without a backup, I DO gig without a backup. I would have no qualms about taking this on the road or whatever. It's built like a rock. I think you literally could roll it down staris and not hurt it.
Case is heavy, stiff plywood.
Real tight construction. Carpet covering and metal corner caps. Knobs are fairly sturdy felling, but they can be pulled off. But this is pretty normal. I think it was a loose screw somewhere, but I could never find which one, and it eventually went away, so I didn't worry about it.