When someone does what Straightarrow does, run a really high FOC then put big ol' feathers in a healthy helical on the back end of the arrow, he winds up with an incredibly stable arrow. It costs some speed and a bit of trajectory, but everything in archery is a tradeoff.
Yeah, I now spend more time dragging heavy deer, instead of looking for my errant arrows. I kind of like that tradeoff.
Actually, my arrows only go about 525 grains - and that's with 20% FOC. They still fly quite flat, since they're probably going around 230-240 fps. I shoot much better groups with these at 80-90 yards then I ever did with my lower FOC, lighter arrows.
I've been shooting arrow with an FOC of around 26% out of my longbow, and really love how they fly, but it's hard to compare them, since I can't shoot them past 35 yards without looking foolish. This winter I plan on building up a dozen for my compound that are in the 25-28% FOC range. I'm betting that they fly even better.