Well my card is newer then Capt. Sopwiths so I'll give it a look.
In my case, it isn't about upping my FPS - on a 60hz monitor, I'm hard pressed to tell the difference as the refresh rate cancels out any gain. For me, it was about removing the hiccups I would get when the FPS would dip from 60 to 58 or 59 fps. I would get a brief hang, especially when turning my head in TrackIR. Fastsync seems to remove 99.9% of the issue. Subsequently, I've chalked up the occasional pause as the sim likely loading something in the distance that I can't see.
