This theme has been cropping up more and more often since U9. Seems to me a disproportionate amount of builds rely on the proc rate of some effect or other, and then those builds are hooped when the inevitable proc-rate-nerf occurs. Add to that the bizarre stacking/non-stacking changes, and it just seems like an endless FotM treadmill.
I just don't ever bother with FoS'd effects. Just build for straight damage and effects be damned. Keeps my build much more stable in the long term without the need to keep chasing new loot and discarding old.