I've used up service loops in the past. Mainly when (as Bikechuck said) I have had to relocate a rack in the room or the room was remodeled and the Patch Panels and switches had to be temporarily "hung" in a safer place.
Yes, they are a pain in the A%# to work up and make neat looking and I think they only provide designers and architects an easy excuse to be lazy sometimes in their designs. But when you need one, pop open the tiles and find one, the sigh of relief is audible from miles away.
