This is definitely the best view you will get of Cairo. I visited the observation deck and didn't go to the café or restaurant. We visited late on a Friday afternoon, which was a very busy time as it's the weekend in Cairo. The lift has limited capacity so we had to queue for quite a while. We did get to see Cairo in daylight and saw the sunset. We visited on a relatively clear day and got a good view but the air in Cairo can be very hazy/dusty/polluted which would limit what you can see. I would recommend a visit during the week and on a clear day.