Comparisons
I can't refute the outcomes of anyone else's comparisons of different vacuums because the posts that I've written above are, again, completely subjective. I don't have a lab or equipment to measure any of the performance characteristics of the machines I have discussed above. I certainly wouldn't try to publish anything I've written above (and, as a scientist, that makes me question whether I should have written it at all), but I don't mind sharing my opinions - stated as such. I think I'm reasonable at assessing the fit and finish, pn effectiveness, appearance of the floors, etc. after using a vacuum several times, but that doesn't make me infallible. Anyone who knows me can attest that I will object to anyone imposing subjectivities onto anyone else as though they were irrefutable. So, I want to emphasize that everything I wrote has no bearing beyond what I prefer to use myself or recommend if asked.
Having said that, I have a lot of difficulty trusting CR's conclusions. Their infatuation with the WindTunnel uprights escapes me. I have never seen one of those machines after use without a completely clogged bagless filter system or a bag compartment full of dust and the body of the machine covered with dust. On the other hand, I've never seen a filthy Sebo, even when using the lower tier bags.
Something that truly impressed me, even though it's entirely anecdotal, is a poster on some (probably this) site who wrote that he built a house years ago when the Kirby Legend II was the current model, used that Legend II on his carpet regularly for the entire ~18 years of living in that house, then changed the carpet and pad, whereupon he discovered that the Legend II had kept his floor clean of even fine dust all the way down to the floor boards. That's doesn't constitute proof of anything, but I never forgot it, and I built up my Kirby collection steadily after I read that.