On another Headblade note my S4 arrived last night and I did my first shave with it this morning. The S4 is awesome, it feels way better than the Classic and Sport.
I picked up a new S4 off ebay but my wife is holding it hostage (i.e., it is a Christmas present). Can't wait to try it.
I found that I prefer the sport version over the original, so am looking foward to the S4 to see if the extra weight makes a difference (even though already get great shave from either the Classic and Sport--have to try S4).