The Nailbomb has a more organic tone, much more open and it cleans up better. The Warpig is ideal for crushing metal riffs, it is comparable to an EMG out put wise but will sound allot less sterile and more "natural" it will be more bass heavy.
The other pickup to consider is the miracle man, which has a very tight bass response and a screaming lead tone.
The ceramic mag in the Miracle man will give you a tighter bass, but will not clean up so well. The Alnico V mag's in the warpig and Nailbomb give you a more versatile pickup with a more even frequency response.