I'm not terribly pleased with mine, but you get what you pay for...
I have the 2nd? generation brackets and haven't punched a hole in my diff yet, namely because the springs don't flex enough to give it enough up travel. I've checked and it looks like it will still hit the diff.
The brackets and plates looked like 5/16" IIRC, and the welds didn't look half bad. I'd hope it's grade plate not just regular mild steel.
It handles bumps like a B---- (I want to put a steering stabilizer in), and the springs give no flex.