Nikon D3 / D300 Vs. Canon

Preamble
There are two major brands of 35mm camera in the pro and prosumer camera market –CanonandNikon. Yes, Pentax, Sony, Olympus and a couple of others have their niches, but Nikon and Canon between them share the majority of the marketplace. Both companies have loaner and rapid repair programs for pros, and rental houses around the world typically carry bodies and lenses of both brands, while rental facilities for the other brands are almost nonexistent.
Economics being what it is, few photographers own both systems at the same time. A couple of bodies and a selection of pro-grade lenses runs between $10-$20,000, and once a decision and investment has been made few bother to switch, or if they do so it isn't more often than every decade or two. Also, brand loyalty comes into play because no one likes admitting that they may have made an inappropriate buying decision. We see this carried to its extreme with the adolescentfanboyattitudes displayed on some web forums and c...