>>423796710 seconds into using any manual focus SLR and they're essentially all the same for regular walkaround photography.
Justifications for favouring one over the other will only show up when people are very experienced; ie the based god Ken Rockwell and I share a particular preference for the Nikon FE, which is great for technical/tripod work because the viewfinder shows real DOF with fast glass, and it will do aperture priority exposures many minutes long, and it pre-fires the mirror on the self timer for max sharpness.