How do I exploit lag compensation, some people told met to turn on bittorrent but it didn't work.

Secondly, the mouse is not as fluent as in BF3. The game's DPI seems to differ when I turn/aim/sprint. The same amount of movement doesn't always equal the same amount of game input.

-Installed Mouse accel. fixer, didn't seem to fix
-Not lagging (50fps+)