Evening Gents,
I too am interested in this pickup, and to answer the question of series vs. parallel, this pickup being a stack, can only be played as either series (both stacks on), or single coil (shutting off the bottom stack) which will give it a volume boost and susceptibility to 60 cycle hum. I plan on ordering one from the custom shop just as soon as I know what specs to order. I wonder if they have different winds they offer for the 1/4" stack.
Right now I have 2 pickups, one is a Nordstrand split coil, which sounds good, but starts out in dark territory, was thinking of putting in a 500k pot to brighten it up a bit. Pickup is very well balanced across all strings, takes well to EQ'ing (Ancient aguilar DB924). The strings are staggered.
The other is a Rio Grande muy Grande, along with the hum, you get a brighter tone, slugs are flat, not radius'ed, I have gone back and forth twice between these two, and when the Nordy is on, I wish I had a bit more treble, and when the Rio is on, I wish it was not so susceptible to noise. I think I am going to try a 300k and a 500k pot on the nordstrand, Nordstrand should consider making one with 1/4 slugs or at least those 45 degree magnet array.