I can't even imagine how bad I'd be in competitive multiplayer. There are just so many weird things to learn and master. For some reason a game like Killzone 3 immediately clicks with me. I know exactly what I'm doing, I memorize the maps really quickly, etc.
In Gears I have no idea how to attach a grenade to a wall, plant a shield in the ground, etc. I know Gears has been lauded for it's controls but I honestly think they are pretty clunky. Just trying to move those hulking soldiers around the battlefield is a chore. I kept asking Grif how to do shit. Apparently placing a shield in the ground requires you to hold one button, press forward on the stick and then press A or something. I kept doing what he said and finally after 30 seconds of mashing the buttons it worked.