Apples to Oranges. My little mini-stable has included both.
The 57/08s are a classic PAF sound, sweet, articulate, etc. IMHO will be regarded down the road as the classic PRS humbucker.
The 408s are even more articulate, substantially brighter, different. They are their own thing, though with tone control, etc., they will approximate the 57/08 sound. Split, of course, they are an entirely different sound from any other humbucker, much more of a true single coil sound.