Well now I am rank 27, it is really important to just keep your points even though you want to spend it on camo and to see/get the classified weapons...the shotty is actually turrible, I wanted to check it out because you can dual wield it, but even then it would suck because all maps are generally big, or at least have a good mix of CQC and distant action. One thing that is pissing me off is I feel like bullets are just not registering or some BS, at sometimes it just feels like the other guy is supposed to win the gun fight, literally no hit markers for me while he ends me in a couple of shots.
And you get an excess amount of points at around 23-24 because there is nothing worth unlocking, but make sure you keep it...there is a lot of interesting stuff that comes up imo.
Actually, the classified LMG is actually pretty good, my second favorite weapon behind the Famas. My third being the Galil and the fourth being the AK74. A lot of people say they have success with the SMGs though over the ARs, but maybe it's just me.
Claymores seem to be more deadly than they have ever been, and they go off much quicker. It is actually worth it to have bomb squad, aka hacker, especially with all the other perks to it. Which brings me to the point in saying that it seems impossible to get pro perks with the challenges you have to accomplish. And scratch that, looking, I am actually 3 grenades from getting scavenger(you have to kill 5 people with grenades that are replenished...kinda hard) and for Sleight of Hand I need to kill 10 people by first shooting at a guy, reloading and then finishing them off after...which is impossible with how fast paced and such this game is.