My last experience of a UK multiplex cinema was pretty much the same as Clandy's.
On the other hand, my favourite city centre art cinema in Newcastle, the Tyneside (which I really miss now I have moved away), reopened last year after expanding its number of screens. It runs an excellent and massively varied program which still manages to be popular, it's comfortable and has two proper bars as well as possibly the best cinema cafe in Britain.
The difference between the two experiences couldn't be greater. On the one hand you have overhyped, overloud, overpriced forced entertainment, and on the other, something actually worthwhile.