I hear you Rick. The way I see it, if you have a 12MP file blown to 16ish x 24ish and compare it to a 36MP file at native resolution of the same face, the details would be quite more distinct on the 36MP file. Would you agree?
Now my neophyte mind says that more aggressive means for smoothing the skin on the 36MP file would need to be taken regardless of choice of method (gaussian blur or a plug-in like Portraiture, etc.). On the 12MP file that is capturing less detail to begin with. This detail that is captured is softened to a degree when blowing up.
I also think that retouching done on a 12MP is softened when blown larger as well but with a 36MP file, you are starting off with a lot of troublesome detail.
Now I am not a big portrait guy at all but I have been able to retouch without going overboard whether it is skin defects or the misapplication of makeup. I just seeing both being greatly magnified on a 36MP file. No doubt, it can be dealt with but as I orginally wrote, I think the way one processes will change. I am scared to death of the peach fuzz I saw in the image shown and how I would deal with that. The peach fuzz I get at times is not as clear and sharp when shooting at 12MPs . I am now investigating how to deal with peach fuzz! I NEED A PEACH FUZZ PLUG-IN.