The Science museum is a sad picture of extreme neglect and bad ideas these days. Just about every museum I've been to in the UK does it better, whether regional ones or national, even the smaller ones. Manchester Museum of Science and Industry, Bletcheley, Royal Arms Leeds, etc.
Bletcheley has a far, far better discussion about Turing and his influence, and far better displays of the Code Breaking work, along with the associated machines.
I last went to the Science Museum about 5 years ago and all the precision models were gone - some of which were so clever and detailed they should have been exhibits in their own right. Just a couple of hints that they once had extreme skill in model making are left. A good chunk of the multimedia and electronic displays and "experiences" were dysfunctional in some way, and a lot of the classic topics had exhibits that appeared simply worn out. The basement "scientific art exhibition" was about 5 token exhibits in a space the size of a football field, and a few dozen people finding somewhere quiet to sit and eat their sandwiches. The top floor (I think) was the for children interactive, sponsored experience. More was broken than not. The cafe with eye-watering prices seemed the most recent and best maintained exhibit.
I was so disappointed - so were the people we took, for whose benefit we made the trip at all. Manchester MSI is far better at being a science museum nowadays. Have to start to wonder if my extreme love of the place in the 60s-90s stems as much from nostalgia and rose-tinted specs. It's deeply sad, and should be criminal, that it's been allowed to decline that far - it was once a world renowned national asset.