Perfect Defense vs. Iron First (Poll)

Alright, I've seen a lot of people using IF instead of PD in certain situations. I was also told that IF is very good and even better than PD, so I tried my luck with IF. IF is pretty good but the short range is annoying, so you vote here, which one is better. Say why and which you vote IF you wish.

P.S; I've been using PD and I believe it's one of the best strategies, that's why I made this poll because I want to know others' opinions on this, the main question is; to you, is IF really better than PD and if yes, then why?