This is just my point of view here, but all you missed by not going on Submission was having your thighs destroyed and blood all rushing into your head. Nothing more. I'm really not sorry to see it go.
I'd have really liked to do the Alton mini-railway actually. I think the route through Haunted Hollow is really nice and I'm always looking for evidence that is no longer there aha, apart from the tunnels that have been converted. There's something quite beautiful and sad about a closed railway, even if it became redundant with the monorail and skyride.