The FO will handle less oil, the PU considerably more. The PU will probably start up sooner, but that will depend on the drilling. One of the top bowlers around here has a FO and it's a very nice, controllable ball.
I would guess that both are versatile enough to be made to react similarly, though given identical surfaces and drills, the PU will still probably be a little stronger.
The PU is a lot newer and may be in better shape than the FO. Both NIB, and I'd probably get the PU.
SH