Controls in the full game are reported to be much quicker and more responsive than the demo and this is especially true for the online multiplayer so I wouldn't worry about it. The reason they are slower in the demo is because the demo is actually based off an older version of the game. To answer Doberman's question, yes the sensitivity can be adjusted.
Also, in case anyone missed it when I mentioned it before:
THE BEST CONTROL SCHEME IS 'ALTERNATE 2' - IT IS ALMOST IDENTICAL TO THAT OF COD.
ALSO, YOU MAY WANT TO TICK THE BOX WHICH SAYS 'AIM HOLD' IN THE CONTROL OPTIONS WHICH MEANS YOU HAVE TO HOLD THE L1 BUTTON TO BRING UP YOUR IRON SIGHTS WHICH MOST PEOPLE ARE USED TO DOING, RATHER THAN HAVING TO TAP IT TO ENTER/EXIT IRON SIGHTS WHICH CAN BE ANNOYING LIKE THIS WRITING.