We visited there tonight with the 9.30 tour slot, ...

We visited there tonight with the 9.30 tour slot, got up to the top by 21.45, plenty of security so don't take anything stupid with you (seen two people have pen knives removed and binned!). The staff were polite, efficient and spoke several languages. The views were amazing, it can be windy at the top so I'd not recommend it in a tee shirt or shorts especially out of season, although I seen some people do it :)