halo is a much better competitive game and more consistent.
BO2 is alot more luck based, but still can be fun. As in when luck is in your favor you can get on murderous rampages that arent possible in halo, but when luck isnt in your favor you will be cursing saying "if this was halo there was no way he woulda been able to beat me"
if you want to play a game where it's not so luck based with an actual learning curve, don't play this game. no matter what people say, this, along with the rest of the cod games, is a casual/twitch shooter.