I've only had Duncan's in the necks of the 4 (or so?) Calis I've had, PATB STK's and SSL something-or-others. I've tried Pro-Tracks, Cool Rails, Choppers, some sort of Lawrence Rail that I believe was close specs-wise to the OBL's, and maybe other stuff, but only liked the Pro-Track and the Chopper. Not suprising since I think single coils sound like crap in the neck position once you get up over 22 frets. -Austin