Danny, we've used a smaller version for a LOT of stress to straighten metal out. The plates been holding so far but i'm sure it will eventually give out!
My first one was probably an earlier (cheaper) design Sean, it blew the bearing retainer and threaded rod out. It was no slow failure either, when it went it sounded like a gunshot and everything came crashing down. Scared the crap outta me!
Just to follow up, I got the T-Rex stands listed in this thread and can confirm they work great with no modifications required for $240. Very stable, I'm pleased with them, especially as less than half the cost of the Pitbull ones. Definitely recommend them.