Play Around With Perks
You will also want to play around with different combinations of perks. Perks provide you with different abilities but you'll only be able to have a few of them active at a time. So, you'll need to choose based on game type and based on your play style.
Perks like Blind Eye (Undetectable by scorestreaks and tracking systems) and Hard Wired (Immune to counter UAV, Powercore, immune EMPs and you will not trigger proximity based explosives or tacticals) will be key in Search and Destroy where the element of surprise is key.
While you might be inclined to stick with your old favorites, we encourage you to branch out during the beta when stats don't count. Who knows, maybe you'll discover a perk that you should have been using in the old games.