Magnificent views well worth the money. Better yet if you get lunch at top of the world restaurant, which rotates, you can then do the observation deck for free.
You can see literally all of vegas. A must to do. A fair amount of things to do in the stratosphere, if you like thrill rides, you'll love these rides at the top of the tower.
Excellent place to take pictures of Vegas from the deck with a 360 degrees view, especially in the evening. It's free with hotel guest key pass. Can get very windy on the upper open air deck.