I'm specifically referring to the crippled K_af2 mount, which does away with the feelers necessary to read out the aperture setting on older lenses (approximate

I'm specifically referring to the crippled K_af2 mount, which does away with the feelers necessary to read out the aperture setting on older lenses (approximately pre-90s). The lenses mount, but you need to go into a menu on the camera body each time you adjust the aperture to tell it how much the lens is going to stop down. I think it's perfectly fair to ding some usability points for that.