I loved it!
First of all, nobody knows about it! Really. I have no idea how that can be, but you can go there on a Saturday night, with no reservation, and you won't have any problems getting a table, without having to wait for HOURS (as is usual all around Mexico City). The view is breathtaking. I don't know about you, but I can be just staring out at the city for ages. Whenever you feel like you need to relax and recharge, I really recommend you go there. Even the prices are OK. It also has a restaurant, but it's not as good as you could expect (we tried it once, but I'd rather stay at the bar section). So, whenever you are around the area, give it a visit. You won't regret it.
All in all, a must-see.