That's what I did sly, a guy I work with bought it for xbox and then for PC (don't ask me why) so he loaned me his xbox and is now selling it to me for $20.
Comparing the two:
Manic's right, you can't really. I have played BF3 almost exclusively team death match, so I cant speak to the objectives. I'll try and give you the pros / cons as compared to a COD shooter though if that helps:
PROS:
- No KILLSTREAKS, DEATH STREAKS
- everything is destructible in the game, trees fall down, when you shoot walls they deteriorate etc.
- Guns are more realistic with bullet drop and recoil (this could be a con too)
- Weapon unlocks seem to happen faster than COD
- You can be a team player without having a 'clan' (medic/engineer/support)
- Acoustics. They. Are. Awesome.
- Graphics - see above
- Knifing - no more knife lunging. Knifing takes two or three swipes from the front, but is one swipe from the back (with a sweet animation) as you slice someones throat and take their dogtags
CONS:
- In core modes, you have to drill someone to take them down. Having said that, to me it seems a bit more realistic but can be frustrating
- In my experience a silencer is a must
- Game controls are similar to COD but setting up your player and spawning is clunky
- Snipers can be frustrating
I haven't dealt with choppers and tanks yet (objective based game types), in my limited experience with conquest I did drive an APC which didn't end very well for me or my team
Hope this helps