Visited here with my girlfriend on a Sunday. After all the glowing reviews we thought it would be quite an amazing place, but were quite disappointed. £13 each plus £3 for parking is expensive for what you get. The code breaking part seems to be the main bulk of this place, with lots of reading and more reading. Some of it is quite interesting.
The mansion hasn't been used to its full potential.. just a load of huge empty rooms!
No need for the ticket to be a season ticket as we won't be returning.