McCarran is an interesting experience. The free WIFI is great, but it is weird to sit in an airport surrounded by slot machines. How do these people collect their winnings?
It is conveniently located nearby the Vegas strip so getting to and from hotels is easy. Be aware though that on the big travel days the lines back up something fierce so you may want to allow a little extra time. It's also worth pointing out that getting to and from the rental car facility is awful. Shuttles in that heat are no fun ... no fun at all.