It's a great show. I have been three times already, going again in February.
Although the prices can seem expensive, if you book in advance (and not on weekends) there are great prices to be got. The most I ever paid for a ticket was 45 sterling and the cheapest 21.50. It is designed that there are no 'bad' seats in the place, so don't worry about being on the edges. Be aware that too close to the screen dulls the illusion of them being real as you notice it is a screen more.