The Observatory Tower is really a cool place to go! From above you can see the entire city (or big part of it). The good points are that it is cheap compared to other ticket prices, the staff is friendly, there is a digital map, pictures etc.They have a photo boot where you can take a picture with your friends and email it straight away and for free! I liked the souvenir boutique as well.
The things I didn't like were the fact that the binoculars work only with a 1$ coin and the timing is about a minute. The glass of the elevator was not very clean. It was very cold, so take a jacket with you :)