Wow - what a strange comparison. So... what to eat - I'm not sure if I want a cherry or an entire watermelon?
They are
completely different pieces of gear. Personally I would not think of the 1.3x crop as a bad thing - if you want it to look like 1.6x, just crop your files in post. The 1D series absolutely kill anything else as far as autofocus and frame rate. Add to that they are a tough camera. Up until a bit over a year ago I still had my 1DmkII, it was fantastic for what used it for (mainly motorsports). I'm a firm believer that megapixels are not everything, I'd take a larger sensor any day. But if money is no problem, then the 1DmkIV, wow - what a camera. I'd bet you would swear you will never need another camera ever again.
But then, like most things, it is just down to money...