Mw3 in my opinion is better than GE, because at level one you can still kill level 80's with ease, as long as you have the advantage of surprise ;), in GE, I could turn around after someone initially shot me and kill them, which seemed a little unfair, but now the engine for Mw3 is more balanced for the guns, only a few are too overpowered and I rarely get a game where more than 4 people are using only akimbo FMG9's or like my favorite set-up an MP7 w/ silencer + extended mags. Killstreaks and Death Streaks also make the game a bit more playable when you first start out,so that you don't start every game like 3-15, kinda the way I started in GE.
GE has it's ups and downs, and so does MW3 for sure, the fact that online is required for spec ops, no predator missiles in spec ops or multiplayer, but the downs for GE to me are worse.
And this is just my opinion.