I've been using AS-VAL for quite a while now, got over 200 kills with it and I can say this gun is very very good. Kills fast and has little recoil, effective on range too, even with it's stock silencer. Up close it simply destroys.
As for the assignment guns, PP19 sucks ass and has bad accuracy from my tests. Only Jackhammer left to unlock, got 5 kills with that DPV jeep yesterday (needed for assignment) but it didn't save/register