If I had to name a problem with coming here, it's fighting people for a seat. But it's popular for a reason - the view is one of the best in town. If you get there early enough it's amazing to watch the sunset from there. The cocktails are good and they play cool music. You can sit back and chill, or dance if you want, and the vibe is really relaxed. If you come later at night it can be harder to get in, and you'll even see queues maybe, but I've never had problems when I get there before 22h.
Calçada do Combro 58, 1200-109 Lisboa, Portugal