I've never used points at Vegas... (And probabily never will for the reasons that ncligs mentioned... Vegas is just too darned cheap on hotel rates..)
My family got a great rate to stay at the Excalibur last year... While the room was nice, it was one of those times I wished I would have had a 1BR.. Keeping food and milk cold for my DS2 was pretty tough, and having a washer/dryer would have been nice.