Gah.
Ugh...
I've sat here thinking about how to sum up my frustration for about a half of an hour now, and all I can seem to come up with is "Kill Whitey."
It's the shooter with the most fun for the casual player, I would say. You can always switch up the way you play with the class options, and there's not too much emphasis on statistics and rank like in games like Modern Warfare 2.