Gareth White, a programmer who worked on Manhunt 2 at Rockstar Vienna, also has something to say on the situation. Among other things, he points out that some files on the disk contain the names of people from Rockstar Vienna.
I haven't played the released version myself, but it sounds like it's virtually identical to the PS2 & Xbox version we finished back in summer 2006, apart from the edits needed to comply with the ESRB, obviously.
From what I hear the people at Rockstar London worked very hard, and I know that they did more than just censor the game. I am sure they deserve their credits. My point is: so did we.