I vote for the Duncans. The 57's are too, well, dull soundiing to me. The AII Pro's are basically potted versions of the Seth Lovers. The Seth's sound awesome but just a tad too thin and bright for my taste. The AII Pro's are the next step up...a little warmer and thicker sounding.
I don't have the alnico pro II, but do have Seth's in my Hamer Special FM and love the tone. My R8 had '57 classics and I just put in a set of Lollar Imperials. The '57's seemed to be brighter, crunch more with less note seperation and have more of a top end bite. I know they're in different guitars but the Seth's have a better balance with more clarity.