Hands- on review of Canon Mk IV I found shallow in the extreme.I have both the D3S and the MkIV, the latter for only two weeks, and already I prefer the Canon as being more intuitive,considerably cheaper, much more of an all rounder---- and capable of superbly detailed results with the right glass.Not to mention the video capabilities which are truly amazing.AS the 7D trumps the D300S, so does the Mk IV outshine the D3S.

Talking about " 'edge' cases': both the 1D M IV and D3s are 'edge case' camers. The D3s just pushes that edge a little harder; both Canon and Nikon have better cameras for low ISO (5D M II, 7D, and 1Ds M III for Canon and the D3x for Nikon). A photographer buying either had best be buying for that edge - dawn, dusk, stage musicals, wedding reception beyond flash range, the upcoming Winter Olympics(read speed) etc. I think the 1D M IV and D3s are two great cameras and the 'edge' goes to the lenses for which you already are deeply in debt.

Talking about "That was silly." Yes but it was entertaining in spite a couple of over the top comments like the spinning set button.

To complain about the menu system and the set button rotating is a bit much considering the reviewer is an admitted Nikon fan.

The D3s has better image quality as ISO goes above 6400, from what I've seen, but the 1D4 has higher megapixel count.

Better cropping and large prints from the Canon, better image quality from low light shooting from Nikon. Both situations are 'edge' cases or small markets. The bulk of the people buying these bodies won't necessarily need those features, but those that do will wonder how they did without this new generation of camera.

Pick your gear or buy both if you've got deep enough pockets.

Other than that, they pretty much are really close.