The difference between PF30 and BB30 is the concern of the frame type, not the crankset. They use the same type of crankset. BB30 involves pressing the bearings directly into the frame, whereas in a PF30 frame, the opening is slighly larger, requiring a plastic sleeve to be installed between the bearing and the frame material. This accomplishes a few things. It allows for the plastic sleeve to take the wear, and then be replaced if necessary, instead of the frame itself wearing out leaving you out of luck. Secondly, the plastic buffer works nicely to silence the creaks that are more typical with BB30 bearings that have been pressed directly into the frame. Plastic is less likely to squeak, so the PF30 is potentially a quieter interface. Thirdly, manufacturers prefer to build bikes with PF30 because the tolerances are a bit bigger for a 'proper fit.' With a BB30 interface, the machining on the frame's BB needs to be PERFECT because the metal bearing needs to fit tight but not too tight, very little range of error before problems show up. But because the PF30 has a plastic sleeve, it's able to provide a secure fit in a wider range of spec error.... This means fewer framesets thrown out during the quality control stage.

-Jeremy