I went out with my buddy Forrest, yesterday. This photo is of him riding, and it was taken with his new Mark II and the 17-40 f/4 L lens. Light is from my 550EX flash and a set of PocketWizard radio slaves. The camera feels pretty much exactly like my 1D, except it's lowest default ISO setting is 100, and you can zoom in on the images to check focus and sharpness. The zoom capability is key. And of course, there's the resolution. But that's not a factor when you're actually shooting. There's only one problem with the camera and that's a max flash sync of 1/250th sec. If you don't shoot sports that probably doesn't matter. But for me it's a big deal. Makes me wonder whether I should even be considering replacing my 1D, since it has a max flash sync of 1/500th second.