nailbomb = louder, more open, scooped mids, treble heavy, very twangy
cold sweat = balanced, but dense midrange, bright top, but not trebly
the nailbomb has more of a classic twang but with heavy metal sort of pick attack (like a duncan '59 mixed with a bill lawrence)
the cold sweat has more of a gilbert/satriani virtuoso type of tone (dimarzio paf pro or something similar)
both are very articulate pickups