oh, i know the differences. right now i have dual-use pickups, humbuckers and single coil. the seymor duncan p-rails would even add a third tone to them. as long as i use the same mounting rings, i think swapping pups should be no problem. i think.
i also was looking at a set of pups that replicate specific tones, in this case, clapton\'s tone from wheels of fire....