At the risk of overloading Lew's brain, and simultaneously stirring the pot, slides make perfect sense if certain conditions are met. First and foremost the frame must be one like a trypical truck. That way slides can be installed above the frame and the frame is never compromised. Second, the mechanism must be such that the slide moves in or out perfectly straight, a likely expense no manufacturer will incur, and lastly, the seal when retracted or extended must be perfect. CObus had experiences with slides that did not meet any of the conditions, and I don't see anybody meeting the conditions for the future either, although I think Newell meets the first condition.