The pathfinder numbers were getting too out of control, without people even necessarily trying to min-max (all rogues stack stealth, for instance) people where having +19's to things at level 7. It was just too much. I've been working on my own conversion, presently in the middle of Adventure 5. Some Players were a little upset with me making the change literally mid-adventure. Some character classes, Ninja, the Gun-Wizard, the Oracle, and Gunslinger had to be totally converted and created from scratch, keeping things from PF that the PCs had previously done, or were skilled in for narrative cohesian. Other things translated very well without complaints from my PCs.
Enemy conversion has been fairly simple, using the MM and Volo's for the basis of many of the Kell-thugs, though even for them, a copy/paste works very well and only requires minimal adjustments. My current challenge is converting Lorcan Kell - who is his own unique Fighter Class in PF who focuses heavily on critical hits (15-20 Crit Range in PF and 20AC without heavy armor). But, so far, the Switch to 5th has been very receptive.