Roger's Imatest numbers were very interesting on several levels but particularly curious was the results of the venerable, 35-year old 50/1,2 AIS . Peak central sharpness numbers were identical to the brand, spanking-new 35/1.4 G and occurring at the same aperture, f/4.
I took some very quick pics with the local pro shop D800 with my 50/1.2 AIS and even wide open I was shocked at how much detail there was (low contrast, but detail nonetheless) in the central portion of the frame. Corners? - Yes those not sharp corners were very well resolved by the D800.
Still, the 50/1.2 AIS is not meant to be a landscape lens viewed at the 100% level on a 36MP sensor whilst being shot near wide open. But for what I use it for (close-in low light candids) I think it will still do quite well on my future D800 (order placed, TBD arrival this summer).
Over at forum.mflenses.com, a pro shooter (Vilhelm Sjostrom) has been putting the old glass to the test and the 105/2.5 has been the surprising disappointment.