Sorry - don't have any experience with the Aftermath, and this is probably the least likely pickup I will get from BKP. But I believe Eric Hellstyle has made some comparisons between the two, describing the Aftermath as having more output and being more scratchy on the topend.
Cheers Stephan
this
I straight swapped them from aftermath -> holy diver -> black dog in my '73 lp custom
the aftermath was quite dry and mid heavy, with a ton of clean output/volume
the diver was less loud and more forgiving, but the voicing didn't change at all
not even less treble, just less picking response
bass was a bit slower, so it might have sounded just a little fuller, but it wasn't bassier at all
from the diver to the black dog, the main difference was a lower output and darker top (gotta mention that only this one was covered), but retained the same kind of mid centered dense tone, just less crunchy/aggressive in the upper mids
also had a bunch of other bkps in this same guitar, but only these particular 3 sounded similar to each other
