For this being my first Call of Duty game, I am amazed.
About 18% through the campaign, I tried the multiplayer. I sucked. Nowadays (4 months later), I get about a .700 ratio even though (Since I sucked in the beginning) My ratio is only like .434.
Lets talk about maps in multiplayer. The best map is Dome (According to polls online), no doubt. And everyone thinks Downturn is the worst, when its one of my favorites (Especially for 3v3 Drop Zone matches.). Personally, I think one of the worst maps is Outpost. It is only good for Ground War matches because it is too big. Also the Face Off Maps were a perfect idea. So all in all, the Maps in Modern Warfare 3 are excellent (DLC Packs are also good even though I only have Collections 1 and 2.)
Next, the guns in multiplayer are also good, even though only about half from the campaign made it into the multiplayer mode.
Best Sniper: L118A/ RSASS
Best Out of Other Guns: ACR 6.8
Spec Ops: Haven't played that much of it, but what I have played, Survival Mode is really fun and the Missions are entertaining (Great how they tell you how much time it will approximately take.)
Call of Duty: Modern Warfare 3 is really fun and great for beginners (aka Newbs) and will have you entertained for hours upon end.
Xbox gamertag: Xtremeistgamer1
Youtube account: http://www.youtube.com/Lhartf1234