Re: Best rock pickup to coil tap?
I'm not sure I understand your terminology. "Coil tapped" usually applies to single-coil pickups, where a third wire is bought out from the middle of the winding, allowing you to use just part of a hot pickup for a less-hot, more vintage sound.
"Coil splitting" applies to humbuckers, which normally use two coils. Bringing out 4 wires (2 each from the two coils) allows you to use one coil by itself, for a (duh) single-coil sound. Both together coil together gives you the full, hot humbucker sound.
That said, my opinion is that the Duncan Custom is a great pickup for splitting applications. It's moderately hot it is humbucking form, and still has enough power to make a great single-coil. The best part is the tweakability - with simple, cheap magnet swaps you can make it a Custom, and CC, or a C5.