Does anyone have a class setup that really works for them? I'm only a 15 in the MP so try to keep the unlock suggestions below that please.

Scar (Reflex, extended mags)
Hammer (Extended mags)
C4... ok a grenade

Stealth Enhance III
Armour Enhance III
Mobility EnhanceIII or if you havent unlocked it point fire enhance, better hip fire.

Scar - Reflex - Ext mags
Hammer
Frag Grenade

Armor Module: Proximity Alarm, helps getting one step ahead of the enemy, and to pinpoint hotspots to get some kills if you don't know them yet.
Stealth Module: Stealth Enhance, very valuable the moment you upgrade it fully, especially when you are a run and gunner.
Power Module: Weapon pro, use this until you unlock energy transfer, it will speed up the game, and get you on track faster without having the superslow reload.