>> The AIS was the best by a bit in the
>> corners, but worse in the center compared with the others... I will need
>> to do some checking of the center of my AIS some more...

Whee-yoo! Larn sumpin' e'ry daa...!
(Sometimes I do wonder at how very long it takes to [re]learn simple
things...!!!) Turns out that my AIS 35 focuses either just to true
infinity, or a hair beyond - and the others were a hair shy (on film,
the infinity images were similar, but the 40-80' images were different
at what appeared to be correct infinity focus in the VF). While I don't
just assume infinity focus is correct (it often isn't), it appeared
correct in the VF with all three lenses, until checked very carefully.
Points up again what an effect a very slight misfocus can have on
sharpness evaluations...