Re: SH-11 Custom Custom
Welcome aboard!
Duncan uses these coils on three production PU's, and just changes the magnets: CC (A2) which is very warm with a rounded high end (and often too dark in an LP), C5 (A5) is bright with scooped mids (usually very good in LP's and SG's), and Custom (ceramic) is high output and a little harsh (especially clean), and lacks the warmth & dynamics of an alnico.
The users have come up with a couple more variants in the Custom series: the C8 (A8) which is high output, with a good dose of mids, and less treble than a C5, but more than a CC. It's a very popular PU here, especially in mahogany, and is used by rock, blues, and metal players. Excellent PU.
The other one gaining popularity is the C5 with an unoriented A5 magnet. UOA5 magnets sound like a cross betwwen an A2 and an A5, with the best of both: rich dynamics, good output, full mids, firm low-end, and moderate treble. To some of us, it's even better than a C8.
There is no virtue in having the same magnet in the bridge and neck PU's. You get no extra points for that. We're far more concerned about getting the right PU and magnet in each location, and that may or may not be the same kind of magnet.