The service is subpar and the rooms are quite dingy. But if you want a room in Vegas, on the strip, in a perfect location, for extremely cheap, then IP is absolutely perfect. I stay there almost every time I go to Vegas. It's right by the monorail, so that's extremely convenient. Ya you can certainly pay triple the price elsewhere and get a nicer room, but how often are you really in your room?
Try to request a low floor. The elevators are absolutely worthless!