Interesting comparison. I've owned the IQ180 (but not the 35LS) and now own the 645Z (but not the 28-45).
To my eyes, in the posted samples, the Phase files do look sharper and hence better if only resolution is compared.
Several points need to be understood in a comparison of this sort, IMHO.
1. Lens: More than the camera, I believe the lens is the key, especially if the sensors are both equally capable. I wonder how the Pentax would have performed say with the DFA 55 or DFA 90, both being modern prime lenses well suited to the digital medium, or if the two systems were compared with zooms of a similar range.
2. Ultimate objective: I may be wrong, but the final resting place of any image must be a print, whether on paper or aluminum or whatever. I doubt we are all happy to just have them sit on a hard drive or on a webserver. In the latter instance, nobody is going to look at the right lower corner at 100% etc. Hence the comparison is useless unless the final destination is taken into account. If it is a print, as I think it would be, then too, the differences at the 'usual' size would be minimal, as was shown so long ago by
Michael Reichmann.
When I bought my Phase IQ180 I was told by all the enthusiasts present that the difference in print quality between Phase and a Canon DSLR would be visible at '8X10' size, a blatant untruth.
Having printed large (over 24X36) with Phase 180, Canon 1DX and now Pentax 645Z, I can tell you that unless you are 3 inches from the print or using a loupe, the difference is not noticeable at all at anything smaller than 20X30 and above that, the Pentax and Phase files are absolutely indistinguishable!
So a lot depends upon what you want to do with the images you shoot. Granted, you can 'crop into' a larger resolution file with greater ease but that is hardly the purpose of shooting with a high resolution camera to begin with.
3. Cost: This is the big issue I think with the OP as it was with me. I discovered that the value for me was not there, given my style of shooting and there were several major limitations to boot. However, this is a very subjective matter and
for many the value is in the joy they get out of using the system and nobody can argue with that.
BTW, I also own the A7RII now and the superb Batis lenses and as I've said repeatedly, the combination of the Sony and the Batis 25 is just about the best IQ for the price and heft.