OK, so here's another approach! A rather dull misty day but very little wind to move the trees around. I set up the cameras with their optimum ISOs and apertures. I exposed so the lighthouse was on the verge of clipping.
Note that my qualitative comments are from poring over the prints, not the screen.
A7r with FE 55, at F 5.6, ISO 100.
IQ180 with SK 80 LS at F8, ISO 35.
In both cases I used C1 to wring the most out of the files (bringing up shadow detail primarily.) I corrected for purple fringing and aberrations though the SK lens was automatically adjusted in C1. I sharpened for inkjet printing. I think the files were about as good resolution-wise as I could make them.
The 36 inch prints, like yesterday, were hard to tell apart and I haven't shown them again. The DR is excellent in both cases, holding all the detail in the lighthouse and in the dark areas under the trees. The Phase file is superior with a loupe but at normal viewing distance there's little discernible difference.
I then printed a crop of roughly half the frame, which would be the equivalent of a 60 inch print.
This time there is no contest. The Phase file is crisp and clean and the sign on the left side is easily legible, whereas it cannot be read in the Sony file. The sky has a subtle gradation not present in the Sony file. The bare trees and the communication mast are a bit fuzzy in the Sony print but crystal clear in the Phase print.
My conclusion is the same as yesterday - up to 36 inches, with the FE 55 lens, the Sony holds it's own. For the bigger print, let's just say I'm not giving up my MFDB!