Not a scientific, simple comparison. I wasn't taking these pictures for comparison, but while post processing i noticed very similar pictures with different lenses and thought it is a chance to compare them. They are pictured with in 10 minutes time difference.
Both images has some small crops and white balance adjusted to make them compare easier.
i removed the ca's in lightroom and they both have some noise reduction. both images have same degree of post processing.
Both image is shot @ f/2.8 and around 1.5 meters distance.
Body is Z7.
The 135mm q is not multicoated version (pre K version 4/4 lens formation), and the 105mm is a late ai-s (serial number is high, just before the sic versions)
I've compressed the images to fit to 2.5mb limit of the forum but the full versions are not different at all.
There might be differences in difficult light conditions but i see virtually no differences between these images.
The 135mm has even better CA's to an extend. (for this picture)
My conclusion is (apart from hars light conditions) there arent any big differences puting these lenses apart from each other.
Sharpness contrast etc are all compareable to each other.
Some minor tint and color cast differences are negitable since they can be adjusted in post processing.
Very impressive for a lens that is designed in 1964s.