series/parallel isn't all that great with a low output bridge position pickup, imo. i've had my PG8 wired up for twin coil cuts, which when both were active it gave me parallel. it sounded like the screw(closer to the bridge) coil with very low output, minus the single-coil glassyness with even less output. that's just my experience though, and i cut output from an already low output source. i've heard good things about using parallel for higher output bridge pickups, and is worth trying in most neck pickups.