Owned BG, played PF.
BG, shot layout is exactly the same on each side. I loved the graphics, I loved the light show, but the game was lacking. Its lock a ball on the left, lock a ball on the right, lock it in the center, then lock one of the balls in the center again, then shoot all the stand up targets before time runs out. The upper playfield is neat, but its nothing that special. The bagettelle in the backbox is fun, I like when something happens mechanically behind the backglass. Got boring over time though. Only lasted me a year or so.
PF, a lot more shots on this one. Only a 2 ball multiball though. Has a ramp which BG does not have any of. BG also has no pop bumpers. I cant comment on the gameplay as much on this one since I only have played it a handful of times.
PF would be my choice.