You gents have already said it, but I find these sorts of direct comparisons a bit puzzling. I have a chain saw, a worm-drive Skillsaw, a 12-inch compound miter saw, and a slew of other tools with which to cut stuff, and I never find a need to compare the results. Just need to know I chose the right tool for the job.
I, too, saw the comparison yesterday and wasn't surprised by the conclusion, but I'm one who doesn't subscribe to the idea of equalizing the image sizes, ratios, etc. I know, I know, it's supposed to be done that way; and it's very meaningful in comparisons like Jack's as it pertained to the P25+, P45+ and P65+ backs because one would benefit from knowing where the line should be drawn in choosing a back for a required output size, etc.
Still, I get more from treating each file with the best possible tools and technique to render a "best case" sample. This sample could be at native output size at a given PPI, or one could (subjectively) choose the largest reasonable print size from each sample file. Then simply observe that file "a" looks great up to "size x", etc. It that's big enough or has the look you want then you're done. Too often (for my taste) folks try to use the same raw converters "to level the field" when in fact it often hobbles one of the cameras (not done so in this comparison), or they stretch and pull a smaller file to match the larger and it looks like c**p, etc.
I have Canon gear and like it for certain projects. I love what my P25+ can do (if I'd do my part) and have it for certain projects. But overall what I really love is that this forum doesn't get caught up in the ridiculous bickering that seems to be going on elsewhere as those in one "camp" attempt to justify their perspective on the other "camp". No need for "camps", just take pictures with stuff you like and make friends doing it. (I've enjoyed reading the observations gathered by those shooting the Canon 5D II - great vibe to the thread in contrast to other fora.)
Thanks for the civility here. It's a pleasure to read these boards. (Sorry for the novel. Slow Sunday here too.)