Pretty much use it's only is against those who crouch after teching generally after bnb combos, however there are times they'll stay grounded or just keep rolling side to side to avoid it.
If you are successful then use FP A+G if you're near a wall or edge of ring (if you're lucky you'll get your desired throw respectively), in open field go for FP B+G if you want to to have a stab at going for high damage. Also bear in mind, depending on the angle, you may get sidethrows as well.
I haven't played much with this in the lab, would actually be great if it could catch rolls, or if there were a grounded version, something like FP 2A+G. I'll explore more on this tonight actually...
AZ