You need to handle theese in a camera shop if you have any confusion. There is a world of difference between a cropper and FF. The 5D should not be $600 more than the D300. Find a different dealer. I'm in Chicago right now but I'm sure I can find a 5D from a reputable dealer for $2-300 less than that. The D300 is nice but I think you really need to know EAXACTLY what you are after before you invest $1800 in a body. IMO this is where Canon shines. The 40D can be had for $1100 + freight. $700 is a major price difference for a couple of features and a lick and a promise that Nikon is going to bring out some new glass.