I've got a Liftco slide on my coach. My rig was built by United Specialties, they went under in '09. I did have some bolts break. I found out the builder used the wrong type and length of bolts. I had great dealings with Liftco customer support when I called to talk about the problem. I believe I created a thread somewhere around here documenting my problem and fix. If I was building a rig (hahahaaha, I have no skills whatsoever to build one) I would certainly put a Liftco slide in. I've heard real bad things about Lippert. Nothing about their slides, all about their crappy 5th wheel frames.
'03 Freightliner FL112, 295" wheel base, with '03 United Specialties 26' living quarters, single screw, Cat C12 430 h/p 1650 torque, Eaton 10speed , 3.42 rear axle ratio