Assault:
1. AN-94 - Underslung - Hbar - Holo/Russian x4/x7 (Always on burst mode)
2. Aug A3 - Underslung - Hbar - M134 x3.4 (Take advantage of the high bullet velocity! Out shoots snipers in terms of distance to seconds. At 640 meters/sec i think)
3. L85A2 - Underslung - Flash Supp. - Holo/Kobra (Low spread & Recoil, but avoid close encounters)
Engineer
1. M4 - Underslung - No attachment/Suppressor - ACOG/Holo (Amazingly accurate. Its identical in terms of stats to the M4A1, but with lower recoil)
2. Scar-H - Bipod - Flash Supp./Hbar - 6x/Iron sight
3. G53 - Underslung - Suppressor - Iron Sights/PK-A x3.4 (I love this weapon, mainly cause it reminds me of an MP5 i think haha)
Support:
1. L86A2 - Underslung - Flash Supp. - Holo
2. M60 - Bipod - Flash Supp. - Iron Sights or 3.4
3. QBB-95 - ??????? (Its a VERY effective weapon is used correctly. I have a hard time using it. But bests the AUGA3 and M98B in bullet travel time)
Recon:
1. Spas-12 - Extended Mag - Slugs - Holo/Iron
2. 870MCS - Extended Mag/Flash Supp. - Slugs - Russian Holo/Iron
3. Mk11Mod 0 - Underslung - Suppressor - Iron Sights (This is a BR that will rock world with its amazing iron sights and tight groupings with a suppressor. It feels like with an other sight on it, its less accurate. I successfully counter-snipe snipers with its iron sights.)
4. M98B - No Primary - No secondary - 4x & Up. (It may just be personal preference since i have seen nothing in the stats that say other wise but when you're on the move and going to line up a shot, i feel like i hit more with this rifle when it has no attachments at all. Downside is, no straight pull.)

As you can see i HATE foregrips with a passion! I will only slap one on a sniper if im not using a silencer, or a belt-fed LMG... and definitely the G36C... the recoil on that gun is so unpredictable its intolerable
Foregirps INCREASE spread, so to me, that sounds like a disadvantage. I'd much rather deal with recoil than to have a bad spread.
Thats why i generally pick low recoil weapons to start with, throw a F. Supp on it and recoil is delt with. Not everything needs an H.Bar.

Im always looking for new kits to use. All the combinations of attachments really alter a weapons feel. I might use a weapon and hate it, get killed by a Level 100 with it, with unusual attachments, and sure enough i'll love it haha.
For example the AKS-74u. I hate it.
Throw a x6 or x7 sight on it, Foregrip(believe it or not) and an H.Bar... and hot damn, you can burst up to 10-11 shots with EXTREME accuracy... a highly underrated weapon.