Yep +1 for Radeon Pro.
FC3 just has problems. I get stuttering (without RP) even with CF disabled. 3 cards is better than two but honestly, it's just bad regardless. Considering it's a Gaming Evolved title, it's a bit embarrasing IMHO for AMD to be this bad in it.
FYI... I've been running RP for a long time, and I've found (for me anyway) that it's most effective if you set the dynamic fps control to roughly 10FPS less than what you'd normally see in FRAPS. That usually gives you enough room to account for any low FPS points you might encounter and keeps things nice and smooth. Even though I'm frame capped, I still get to enjoy all the eye-candy just at less than max FPS.
I'm really hoping the frame pacing driver is as good as it appears to be... If it is I'll be set for another year+ with my current build.
W7 Ultimate x64: Corsair 800D, AX1200
EX58A-UD5, i7 970 @ 4.5Ghz
16GB RipJaws @ 1600
3x XFX BE 7970 Tri-Fire @ 1200/1600
OCZ V3 120GB + WD 2TB Black
Creative X-Fi Titanium
Dell U3011 + WFP2407
Koolance 370 & EK GPU Water Blocks