Be careful with cocktails. The drinks on the menu are fine. However they mix anything you want. The problem is the outrageous cost. We paid 115 Dhs for an Apple'tini. The view was not good (at night) due to dirty windows. I am not sure if this is the normal condition or we just had bad luck.
We did it in February. Unbelievable what these cars can do. I'll always remember the "Arizona speed bump". The driver told us many interesting stories, too.
The view from the sky deck is just stunning. Don't miss it. The exhibition in the basement is rather boring. You can read everything in the Internet anyway. Take the elevator and just enjoy the view.
... only when the weather is fine. There are some not-so-expensive cafés, many shops, the main train station on the one end and the Altmarkt on the other.