I doubt either will sound cr@p :)
To me, it depends on where your priorities lie. If you want a PAF influenced pickup that has a very tight bottom end and has a gritty, edgy distortion that is 90s Metal then get the Nailbomb. If you want a fatter, smoother and more fluid pickup with the sweetest lead tone you can imagine and is more influenced by 80s Metal, get the Holydiver. I've tried both and they're really not that similar. Perhaps think of a few 90s Metal bands and what they're basic tone is like, then think of some of the great 80s style Metal players (John Sykes, Jake E. Lee, Doug Aldrich etc.) and simply go with which core tone you like best. Personally, I've found the Holydiver to be extremely versatile. It copes with Modern Metal styles but retains its 80s characteristics.