So just a teaser report at the AM break, we can put one thing to rest: Initial image reviews comparing the S2 with the 180 mounted, the P40+ with the 150/2.8 AFD, and the P65+ with both the 200 APO manual and the 75-150 zoom in the studio, all shots at approximately the same image magnification ratio, the bottom line is the net detail at the pixel level is virtually identical between all these backs and across all of the lenses. Of course this makes sense given they are all 6 micron backs, but requires the lenses deliver at that resolution and they all appear to be doing so -- and also insures that any technical sloppiness will be seen. For example, even at f11 and portrait distances with any of these combos, what I'd consider crisp DoF was maybe an inch tops. Also note, the P40+ and the S2 have about the same number pixels across the frame and the P65+ obviously has more, so gives you a wider view or some cropability or both over the other two...
PS: We won't be putting any images in this thread, but will load the official review up with them, including a bunch of raws from each camera you can download and play with.