Isn't it funny, the perspective you get from seeing something on a tv show or in a film. It apparently appears as though you could just say hi to the reception desk then potter on up the lift to assess the view.
Ha ha, not a chance. We had quite a lengthy queue through the exhibition area, then worked our way through security, queued for our ticket and then more exhibition before getting to the first lift.
Our transition was helped by courteous friendly staff and other tourists, like ourselves, were in no particular rush so it flowed without any issues.
I was a little surprised to find that if we wanted to go further up we had to pay an additional charge. When you're scheduling and budgeting for a family visit it would help to know these things first.
I definitely recommend this iconic building as your choice for a view of the city.