On the primacy of exposure

Again, how did you alter exposure in the original images? That plays into it greatly.

As far as the dif goes....pic 1, 2, and 6 show significantly more loss of detail in the highs than the other 3 (roof left center). 6 almost looks as if the shutter speed was to slow resulting in motion blur. At the other end the shadow noise in 2, 4 , and 5 seems significantly higher than the other 3. Light was indeed changing slightly. So I'll go with 1 and 6 being most overexposed (loss of detail in highs) and 5 being closest to optimal as it seems to retain the most detail overall. Obvious major differences in the 6 images so if indeed only exposure changed (vs light, motion blur, or focus) then exposure is indeed critical. Not sure if the real dif in the images can be attributed to just exposure though as much detail lost due to what might be focus blur or soft lens at some apertures. That was fun.