I have had one on every truck but one that I have owned for the last twenty years or so. Have a Leer just over bed height on my 2005 Tacoma and, like most of the posters above, find it very useful for hunting gear, fishing gear and travel items. I have a utility trailer with a 6' bed for smaller items that won't fit under the camper shell and a 12' double axle flatbed trailer for the really big stuff.
My wife hates them, though. Says that a pickup should have an open bed so that one can haul anything that will fit between the rails. We were looking at new Ford pickups this past week and she make me promise that I wouldn't put a camper shell on the new one. I promised, "at least not right away".
