Originally Posted by
Raptorg
imo it's either Imp IS, or Imp Faerie Fire otherwise you give up too much points.. You could go for 3% more crit by taking both, but I don't think it's worth to give up those point you could have put in resto(Intensity or Master Shapeshifter at level 80)
At level 70 you could take both by giving up Furor, without any immediate loss of damage. But considering that we'll be leveling to 80 in a few weeks, It's barely worth speccing that way, knowing you probably won't have both at level 80.