This will be the last Assassin's Creed I ever buy.
I was playing AC: Revelations last night and got frustrated with the controls that I had to turn off the 360.
I felt the same way about Brotherhood but heard great things about Revelations (And got it from GS for $20) so I thought I'd give it a shot.
The contextual controls become confusing and it appears that some button functions are illogical. Sometimes, I'm expecting to interact with A or B and the real answer is X. My real frustration comes from doing anything that requires precision running. Ezio clumsily misses the cable he's supposed to tight rope over and jumps 4 stories down to his death or is hopelessly off course during a race. In the first Constantinople sequence of AC:R, I wa schallenged to use the hook to climb some tower. 3/4 of the way up, Ezio decides to jump away from the tower instead of up.
As a completionist, this is stupidly frustrating. I like to play the game, the way the game was designed but the design doesn't appear to be conducive to completing achievements. I appreciate challenge but this is just broken. It's one players opinion. AC: Revelations will be the last game I buy.