Three words will some up my session so far tonight. One Man Army. I've been using it with my trusty M16 Holographic but my word does it open doors, yet it doesn't feel cheap (unless you use it with a tube of course!). Unlike Battlefield I don't have someone to give me extra ammo, I burn through it alot because I stay alive alot, even Scavenger Pro fails me sometimes. I also like to use stuns to check corners and such so it's proving very handy on a defensive set up, and when it's time to offence give me 5 seconds and I'm ready for it! That said so far I've just changed to the same class again to get more ammo.
Also using Sit Rep pro now which is an extremely useful perk, serving me well indeed, combining both in the past 3 games (which is actually my first games since getting SR Pro and using OMA full stop) and my WORST game has been 21-5 using 3-5-7 Streaks. Best was a 40-3 including a quad semtex kill for good measure. In just those 3 games I've racked up over 70 OMA kills (streak rewards don't count either!). Whether I'll completely phase out my normal Scavenger Pro I'm not sure, but it's a contender as it increase my flexibility. The question is do I really benefit from changing primaries that much without a secondary to begin with.