Nailbomb really sound great in drop tunings, I recently installed Alnico Nailbomb in the bridge of my PRS Custom 22, and Cold Sweat in the neck. Very common, almost classic combo here :)
Lowest tuning I play is D, and Nailbomb delivers punch and aggression, without being muddy or flabby.
Cold Sweat is amazing flid neck pickup, crunchy under good ammount of gain, and very bluesy, when you roll down volume and tone :)