Re: JB-neck?
If you like to play loud and also like a genuinely clean tone for chords, it's hard to get that from a neck humbucker wound over 8K. The JB is wound to 16.4K or more!
I suspect that the folks who like the JB as a neck pickup do not play clean chords through it at high volumes. I suspect they're rockers who play with a semi distorted to totally saturated lead tone and like to drive the daylights out of thier amps.
The JB does that beautifully if that's your bag...and it will split into a great sounding and clean single coil.
Personally, at full output it's not clean enough for my tastes to use as a neck pickup: sounds dark and wooly to me.
For the neck pickup, I'd go with a Jazz or 59N...or A2Pro or Pearly Gates.
Lew