I took 4 children to the London Dungeon, aged between 8-13. As I had previously been to the original site at London Bridge I knew what to expect (children had not).
I read the reviews on tripadvisor prior and noted that the singles were not that impressed but families seemed to enjoy.
Our trip was really great- the fear and fun factor for the kids was just right, although my 8 year old did get a bit freaked out at times. The information was delivered in a fast fun fact way and the actors did a good job of engaging with the audience.
We sent 1.5hours going through the experience which was just right.
Overall I think it was money well spent and we all thoroughly enjoyed it.