[JackMonroe]

In MW, there's a greater potential for some players to be better than others, compared to CSS; a potentially greater skill difference.

That is so very false.  The game is easy to start and easy to master.  During the free weekend of black ops on steam, I got to the cap of 30 in hours and got called a hacker at least 10 times.  Back in COD4 I played in scrims and pooped on everybody and again got called a hacker over and over.  That is with me just picking the game up on the side.