They've revamped a lot of the multiplayer aspects in an attempt to reduce the swiftness that people seem to die with. The new support strike package system should definately help you out in terms of surviving longer and in regards to the twitch gameplay maybe try sensitivity 2 then build up. I took a break from gaming and when I returned i had to reduce my sensitivity all the way down from 8 to 2 just to ease myself in again.
I played CoD maybe one time (one sitting... I played for a few hours) in the past 3+ months. And I sort of miss it. I wish CoD had servers, I wish they'd fix the crap, but I still miss it. I guess because I'm good at it, it was my first multiplayer series, and so on... and maybe because I played the BF3 beta and didn't like it.
Camo options that appear in MW3: Classic (looks a bit like woodland but with more tans and contrast) Snow Multicam Digital Urban Hex Choco Snake Blue Red Autumn Gold Autumn I'm thinking is just fall camo from mw2, digital urban is digital from previous titles but with a new pattern and choco is the new desert (but less yellow more brown) I guess red and blue will be the tiger stripe patterns from previous mw games and snow will be a variation of MW2's artic camo which has purples and blues added to it, Multicam is like a more green looking tiger stripe pattern. Hex and Snake are a mystery to me though.
I really wish there was an FPS where you could design your own camo that would be sweet. Not sure how I feel about gold camo in MW3, Black Ops' gold camo ruined the novelty of it and MW3s system for camo doesnt seem much better (you get gold for reaching lvl 30 on the respective weapon)