I have an alnico humbucker at the moment, but I play a lot of experimental, screamo, post hardcore stuff.

Would P90 be better? I'd be putting in the Gibson P94, as it's the humbucker version of the P90.
Stick with the humbucker if you play screamo/anything with a bunch of distortion.
There once was a man who really loved salt
So he tied his nose to the sea
And then God came down from his silver throne
And said, 'Honey, that water ain't free