We still play 3.5E.
The reason is mainly inertia: most of the group don't know sqauat about PF, they aren't as Forum/ Internet RPGeeky as I am

. And most don't have a ton of spare cash (I know I don't) with which to buy new product.
So, our trusty PHB's and splatbooks get dusted off and we carry on with the old rules.
And, to be honest, these rules do us fine. They allow good customisation of characters, even within the same class, so that PC's can be unique and flavourful. Feats and skills allow the martial classes to go their own way, whilst clerical domains bring different powers to the worshipful. And, as always, mages proved that skinning a cat does not always involve a knife.
PF does just the same, but with more HP and an improved Grapple mechanic.
That said, I have added
Trailblazer Action Points, Encounter Design (XP Budget system similar to 4E) and XP Awards, Skill Challenges a la 4E and 1hp minions based on an old post somewhere on ENWorld.
And as far as 3.5E goes, I have a ton of stuff to run for the game which will take
years to accomplish, and I don't have time to do conversions!