I live about 2 minutes from the Cosmo, and it's really hard to list everything that makes this place so awesome. A ton of great and unique restaurants(Holstein's, Secret Pizza, China Poblano, Milo's), a fantastic concert venue(they drain out the pool for GA shows) and an incredibly modern and young feel. It's legitimately more exciting being in the Cosmo over any other casino in Vegas.
I haven't stayed at the Cosmo but I have been in the rooms and like everything else they are very very cool. From the views to the comfort of the beds, it's all very high class and worth the price tag.