Though I do agree that doflamingo is stronger than base luffy and even gear 2 and 3, I still have to admit that doffy was clearly outmatched against gear 4. IMO it would go something like this:
Doffy >> Luffy
Doffy > Gear 2 Luffy
Doffy > Gear 3 Luffy
Doffy < Gear 4 Luffy
I am by no means saying doffy is weak or that he could not beat luffy fresh, but it was made very clear by these last couple of chapters that
You must be registered for see links
by doffy himself. If he outlast luffy, which he clearly did today then it's no doubt in my mind that he could defeat luffy, but I dont think you should say that doffy is stronger than Gear 4 because that certainly isnt the case.
By the way, if you pay attention to the past, I feel this arc will make people look at doffy, much like they looked at crocodile after the Luffy vs Croc fight. Even though crocodile won 2 out of the 3 fights, people still think to this day that he is weak (which isnt true) because luffy won the 3rd fight by plot. I fear that people will say the same about doffy.