I play zombies, I'm European though.
The thing I hate is that you lose your rank if you don't play once per day, I was level 5 with skull that had blue eyes, now I'm level 4 with skull that doesn't have them, the blue eyed skull looked so cool
I've only played one Grief match and that was in the town, it wasn't funny at all since there was some 10 yearld kid who explained to everyone that you're supposed to make the other team lose, well before I went down, I managed to gather a hoarde of zombies attack those jerks who constantly just stole my insta kills and pushed me at the lava when I tried to pack a punch.
Grief might be better in the farm, it is a small map, but at least there is no lava and fire, it really ruins the town which is bit too simple already.
Tranzit is the best mode just because of the large map, there are easter eggs, teleporting and pack a punch is there as well, but getting to it seems to be impossible without proper team work. Treyarch made it bit too hard on my opinion. I've not been able to get into a team that would go and turn on the power, there are few secret places that I know about, but never get there with the power on.