I don't have any complaints about this game, except I can't find a match by myself (sometimes I can, it'll take around 10 minutes). When/if it finds a match, it usually kicks me out and says "the modern warfare 3 servers aren't available." Weird thing is, I have 2 Xbox 360's in my house, one isn't mine. The other 360 can find matches with NO problems, instant matches. The only time when we can find a match is when I party up with my friends and if it doesn't pick me to search for one. It isn't my router or modem, considering the other 360 is hooked up to the same one and can find matches fine... and I haven't had this problem with any other game I played online (Gears 3 finds matches instantly). My NAT is open. My connection is solid and recently upgraded it. When I play with my friends, I barely ever have any lag or hit detection issues, only once in a while. Just makes me mad that I can't play by myself and have rely on when my friends to play.
I seen this similar complaint before, but from Europeans. I'm in New York.