Alnico is more organic and a bit warmer than ceramic, possibly a bit more articulate. Most ceramic pups are tight and agressive, this is a generaliation of course. Ceramic usualy has a bigger bottom end, and again, tighter. The winding of the pup is hugely important but you get the general idea. If you play a lot of hard rock and metal then ceramic will do you very well, it's not a one trick pony by any means, but you buy a pup that suits the style you play the most.
I like both sounds, between me and my wife we have Warpigs (c), Cold Sweats(c), Painkillers(c), Nailbombs(a) x 2, Black Dogs(a). I must confess the painkillers haven't had a proper trial yet, I've gone off the guitar they were put in just after I made the swap (not becuae of the tone). The others all sound great, are very versatile, have great definition and can easily play styles outside of their 'target' style.
'Hotness' is very subjective, DC is used as a common guide and is a useful measure, but life is never simple, again the winding of the pup will effect the way it sounds. The higher the DC the more output a pup will generate, but how it sounds will depend on it's frequency response.
To use BK's as an example,
the Warpig is a 22k bridge and the Miracle Man is about 17k, so the WP should be hotter. However the WP is a bit mid scoped and the MM is a lot stronger in the mids, so the MM probably sounds like a hotter pickup because your ears respond to mids more than bass and highs. (I've never done a direct comparison, I'm guessing a bit here)
DC is a good guide for 'ballpark' comparison, but a difference of 1k either way you'll not notice, the way the pup is wound will be far more important.
