PLEASE stop telling summoners to use Ifrit!!!

[xxalucard]

but the 4 seconds every attack is pretty much what kills it for ifrit.

I agree, this is the main factor above all that did it for me too. I'd also like to say the spell speed really isn't that helpful since we don't gain much from 20% of a 2.5 second cast (a few tenths of a second maybe?) and half the time that occurs you've already finished casting your dot rotation.

EDIT: After actually watching Ifrit attack I am convinced that the reason he delays burning strike is because of his auto attack, animation lock must be it. But think about it, he is delaying burning strike by one second or so to auto attack which when added together are either the same or more than windblade , is that really a net loss of dps?

yes