I hated the Battlefield series until Battlefield Bad Company 2 which was hands down the best multiplayer yet IMO. Up to that point I was strictly a COD person.
I abandoned COD because it seemed like with each release map sizes shrank or the design made every close quarters which causes round after round of spray and pray battle. I like some tactics to be involved and love the vehicles.
COD just doesn't do it for me anymore. I will try the new COD when it comes out but this one is on pre-order. I don't have much confidence if the last COD game is any indication.
I felt treyarch made massive maps and infinity ward made the smaller ones. I prefer small maps with tons of action. I dont have enough time in the day to sit in a bush waiting for people to come.