I concur 100% with what I think is the "REAL" reason for this thread, and that is that one should not be apologetic with the equipment one has. And this is particularly important for "novice" and "newbies" who may be intimidated by some of the cameras one see in photoshoots. I have seen cameras that can be successfully used as missiles!
Enough have been said about the fact that it is the photog and his/her vision that is the most important. There is absolutely no question that the vision is paramount. But the photog should also have an awareness of the limitations of one's equipment. There is little point to use a low end P&S to try to take the face of a spider. However, excellent shots of models can be taken with just about any camera.
Having said that, EVERYTHING ELSE BEING EQUAL (emphasised!), the bigger the film, the bigger the sensor, the more pixels, do in general give better quality. Pointing out exceptions to the "generalisation" do not prove anything. I am not talking about the image content. I am talking about image quality. Some of my favorite photogs use 35mm only!
For myself, I use 35mm rangefinder/SLR to medium format rangefinder/slr to large format. I always have my Leica Minilux in my pocket when I travel for really quick shots.
I must admit that some of my more memorable shots were taken with my Minilux!
I like portraits, and had use 35 mm SLR to 645. But having photographed with a largeformat and saw the difference in quality, I wonder if I can be happy with a smaller camera. Of course quick changing scenes are harder to photograph, and I must change my mindset in the way I do my photography!