Absolutely great view on a gorgeous day, definitel...

Absolutely great view on a gorgeous day, definitely worth it for a once in a lifetime experience.
However, be prepared for a lengthy queue, it's hugely popular and will take some time to get on even if you pay for the fast pass. We went on a fairly warm sunny day and it was heaving. Took just over an hour of queuing outside, after the queue for collecting your tickets. PS the A queue starts fair bit away from the attraction, but it does move regularly so it's not so depressing!
Top tip: make sure you check online for 50% off ticket offers, etc... it will save you a packet. We had a 50% off offer included as part of our train ticket down to London.

Enjoy!