Intel I7 3770k Or AMD 8350 Or Intel I5 3570k?

See, I have a AM3+ motherboard, and currently a FX 6200 clocked at 4.2GHz, thing is, I feel when I try to play say BF3 on a 32 man server, My pc run's smooth, yet come to a 64 man server, My PC feels sluggish and well fails. Now I know Its going to effect my FPS and CPU usage with what settings in game am I running, well Ultra I don't use I mainly use a mix of medium and high, to Me its all about performance before eye candy, but BF3 seems to have no performance boost the lower I turn the settings down, I mean with one card I get 98-99% usage but in SLI I get 50% on each card with v sync disabled and on ultra I have even tried with settings on low and enabling v sync, lol that is just worse! I have been told the higher the settings, the higher the usage, and my cpu seems to be lagging behind.I know there is things to take into consideration like the Ram, Graphics, Hard drives, Lag ect, But I'm running two GTX 480's, 2 Velociraptor Hdd, 16GB Corsair Dominator Ram, a Corsair HX 1050w psu and Windows 8.Come January I'm planning a upgrade, but what My dilemma is should I move to Intel has I feel my issue is a major bottleneck with the 480's and my CPU, I don't want to buy a 200 cpu (8350) and a few months down the line have to invest in a Intel because the Pile driver has failed like the Bulldozer did! Or just upgrade to a Intel i5 or i7, I mainly game but do video work as well, even considering getting a i7 2600k or 2700k,