Does it matter? Your FF should overwrite the Feral FF anyways. I guess it could matter in the case of having a Shadow Priest in the group and wanting the extra global for dps. /shrug.
Balance druids everywhere are holding our breath waiting for a blue response on this... you should see us all turning purple (even the Horde ones)!!!
Seriously, though, the number cruncher types have tried testing many times and the random nature of crits combined with the small % difference makes it inconclusive. If we knew whether it was intended to work this way, many of us would reconsider IFF as being a worthwhile talent. As it is now, if we have a shadow priest for Misery, the vast majority will find someplace else to put those 3 points.
Come on GC, it's been 3 or 4 months on this issue, a straight one word post containing the word "yes" or "no" would do. Hell I'll even take Kalgan or Tigole at this point.