My slide is a Liftco. I'm pretty happy with it. It came with the coach so I have no idea how it was to build in. Mine is just for the jacknife sofa so it only goes out about 2' I guess. For a sofa sleeper I think you would want it to go out further. But the jacknife doesn't fold out as far. Mine has two long threaded rods that drive it out using one motor under the sofa. No problems in the three years I've owned it. I do prefer to push slightly on the one side while running it out just to keep it even and give it a bit of help. Same thing running it in I pull slightly on the one side to keep it even. Maybe I don't need to do that but it makes me feel better helping it out.
'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