Fan-effing-tastic.
The multiplayer is based on an XP rating system. The higher you get in the ranks the more weapons are at your disposal. You can call in air strikes and even helicopter support if you gain a kill streak long enough but trust me it's tough.
The one thing that really separates this game from other FPS games is the amount of polish they applied. It's everywhere you look. To your enemies yelling in foreign languages to the shrapnel and bullets you hear flying by. You even see the differences in the little things like bullets holes stay in the environment. This is what made a good game a great game.