I had a Go City pass and this was one of the attractions you could include. There was no need to book a time, simply show your pass and the staff will tell you when you can go up. We arrived around 10am and we were told we could go straight up. No queues and no waiting (other than security screening - airport like). The whole place is very new and modern and looks slick and elegant.
The ride up in the elevator is fast and while you go up, the whole light becomes a 360 degree screen of the area outside, pretty amazing. However, as you are in the lift with others, you do not get a perfect view of it.
The viewing platform sort of protrudes from the main building and it is spectacular. It has glass walls all around it so you get full views of the whole area. There are staff members keeping everyone safe and this felt reassuring. We were not rushed at all and it was great to be able to sit down and take the views in knowing that you do not have limited time (no one said anything to us about time limits, so i guess there is none). It was busy enough but not crowded.
There is an extensive gift shop and a bar.
Two things that did not work for us. Staff at the bar looked like they could not be less bothered to be there, acting rude when we ordered some drinks. Also, as you leave downstairs, you can buy photographs of your visit. We paid for the full package and the folder we were given was damaged. We told staff and they changed it without problem. The second folder was also damaged but they did not show it to us. It was only when we were about to leave that we realised this. They did change it again and all good, but I could not help and feel that this service needs to be a lot better when you pay short of $50 for it.
We checked the weather forecast ahead of our visit to choose the best day while we were there.