When I spoke to the guy at PVC Cages he stated he has never ran into any sagging, so without any proof I'd more then question the sagging issue as there would be a lot of complaints which would hurt his business. If there's a known issue on something like that, word would get around pretty quickly, like a bad breeder. I'll likely give him a shot at 2-3 cages, and I definitely like the fact he uses an LED fixture, though he doesn't know if it can be dimmed or not.