I would have to say that Ifrit benefits off of int, there is no other way his damage will continue to go up since my str has been static for a long time. Currently his auto attack + burning strike do the same or more damage as Garuda's Wind Blade. Often more since both his auto attack and burning stike have a chance to crit.
His enkindle does more damage than Garuda's. Has a dot effect on top of the initial hit.

Is he more dps than garuda? I cant say.
Why he has burning wall though >>.

Given though that he hits more often and has more opportunities to crit, it is worth considering the increased chances of increased spell speed he can provide that gardua cannot.