When I saw the perk list before the game came out I thought it was a little daunting and a little ridiculous. Thinking about it for a little bit I must say that it's better than having a perk like Assassin Pro or SRP which did so much. I do wish they copied the system used by blops2 which I liked more.
Other than that and some crazy spawns I have very few irks (I wouldn't even really call them complaints). There doesn't seem to be enough unlocked as far as weapons go and I'd hate to unlock something I don't want when it takes so long to level up.
My only other issue is with Squads. I haven't had any time until now to put in a good session of MP so I've been playing Squads which is fun. The only issue I have with it is that TDM dominates the holy hell out of it. I think since release I've played around 30 games. Of the 30 I have only played 4 that weren't TDM and three of those were either Dom or KC...the last being Cranked. You would think that the new modes should take up at least half the games.