there is no noticable difference to my ears between f-spaced and non f-spaced pickups. You can mix match them all you want to , but some will argue till they are blue in the face that it matters .
f-spacing just reffers to the spacing difference bewteen fender/floyd rose style bridges and the gibson string spacing .
the paf pro in the neck is fat and round but still has good top end . You can pull
pinch harmonics out of them .
the paf pro is one of my favorite
neck pickups . As for it in the bridge , i didn't care for it at all .