My 4/70-200 mm lens show some improvement at f/5.6 and get even a bit better at f/8. The lens is good at full aperture and images taken with it is contrasty and show fine color even wide open. Some degrading perfomance towards the extreme corners. Just as expected for a lens in this league.
This is not a perfect lens, but it is very good - and quite handy too. Very pleased with mine. And even my CaNikon foes (we are playing that game in a very friendly way) are impressed with images taken with this lens (even knowing it is a Sony lens)! ;-)
Have several Sony lenses and no problems in sight. Are testing every new lens extensively for sharpness, curvature, seidel abberations, reflexes and hot spots in the center of the field of view (common with several cheaper lenses but have not seen that mentioned often) - and then some.
My number of tested Sony lenses is statistically dubious (about a dozen E and FE) but no lemons hhage been found here, not a single one. Some of the lenses show slight deviations from perfect centering but that is also something expected in this price class (even my 1.8/55 is ever so slightly unsymmetrical but nothing that shows up in real life images anyway - so in that regard not perfect, but still more than good enough).
So real life use or reviews - the 4/24-70 is not the worst lens to collect. And the sample variation hysteria have yet to reach my local world. :-D
I would be very interested to know how you are testing the aberrations of the lenses. Short of a Shack-Hartmann sensor or an interferometer, they cannot be easily measured. Even then, both of those methods will return a measure of the wavefront from the lens, which you may evaluate with zernike polynomials, and not the Seidel polynomial.
Have to dissapoint you here!
Have been playing with camera lenses, enlargerrs, projectors, microscopes and telescopes all my life so optics is simply something interesting me - but my professional life happened to fall far from that area of interest. So just into it for the fun of it - and even having a hard time to be dead serious about it.
Not beeing an optician I simply take the ordinary test photos + star testing + using a homemade optical bench. Using video recording to watch the results (using the ImagingSource camera as base).
Nothing fancy, just enough to get an idea about what is going on. Testing for coma, astigmatism, longitudinal and lateral chromatic abberation - no scientific results, just seeing trends (which I guess would be verified by stringent testing). Just beeing curious so this is a fun project - nothing more and nothing less. Guess I am also guilty of mixing in some (more or less conciously) black art into my testing but that is a common mistake by most amateurs...
Anyway, seeing some interesting trends and getting to see the optics from another angle. And have to admit that a professional migh find my setup a bit odd... :-D