On the whole I think they made a pretty good fist of it, Alec Guiness will always be my George Smiley but Gary Oldman gave it a pretty good shot. Toby Jones as Alleline was instantly hateable, and John Hurt gave 'Control' some more flesh on the bones of the Alexander Knox 'Control'. Benedict Cumerbatch was not right for Peter Guillem and Tom Hardy too young for Rikki Tarr, the story hadn't been mucked about too much, obviously time restraints played a part. On the whole though I liked it, a lot, so much so that I going to give the book another read.
I bought and watched it on BR last night, not seen the original or read the book, and I absolutely loved it. The atmosphere portraied was eery and I don't think I've ever seen Gary Oldman this good. I've hated past performances by him but this was in a league of its own.