Originally posted by biz-engineer ...MF is especially good for making XL prints, and hads no advantage for printing in a magazine.....
This is not entirely true because you assume that the only advantage of MF is its high resolution that enables XL printing. That's only one dimension of the MF advantage.
If you downsample a 16-bit 150 MPix Phase One image to something like an 8 MPix file for A4 printing at 300 ppi in a magazine, it seems like a waste of pixels but it's not. It creates an image file with probably about 17-18 EV of DR. The result smokes the pants off APS-C for highlight protection, shadow recovery, high-fidelity color, and high-iSO work. That downsampled Phase One file will be much much more tolerant of extreme processing than the best APS-C image.
To a first approximation, any photographic system that can gather more total light can create both bigger and smoother images. MF can provide both more pixels and more bits of data. The total amount of information in an image is strictly upper-bounded by the total number of photons measured. That's not to say that lens aberrations, flare, read noise, dark current, and other disturbances can't impair the information content of an image but it does imply that if the system collects fewer total photons, there's no way it can resolve as many pixels or as many bits of light/color.