A few things:

1. ISO - I shot at ISO 100, as this was not a noise/sensitivity comparison. I expect the 50D to handle low light much better than the 1D Mk II and it does for me. Of that, there is no question.
I just expect the 50D to provide decent image quality at ISO 100, which I can't seem to produce. And more importantly, I shouldn't have to work this hard. It took 20 shots AND an hour fooling around with AF Microadjustment to get what I got - that to me is unacceptable for a $1000 camera, pro or not. The better ISO sensitivity (dynamic range?) and higher native resolution *did* capture more shadow detail, even though the areas were soft (see full JPGs). But that detail seemingly comes at a price - too high a price for me - with a sacrifice in overall image quality.

2. Pro vs. prosumer - I understand the 1D is a pro camera. I would expect nothing but the best image quality from a 1-series. I've had many 1D's and 1Ds's over the years, and they have never failed to disappoint. But back in the day, technology and quality seemed to trickle down. Resolution, sensitivity, and speed were always higher on the premium series, and slowly made their way down the food chain. However, it seems like Canon is taking the reverse approach. Is it that these technologies are still a bit too "beta" to sell in their 1-series to pro shooters? The 1D Mk III was criticized for being "only" 10mp when lower cameras in the Canon lineup were of equal or greater MP. Though I'm still not totally convinced that the Mk III was a great step up (Canon never got me to part with my Mk II, and I know plenty of people who agree), it seemed as if others in the prosumer lineup eclipsed much of its performance on the spec chart. This test still convinces me that the best all-round camera made (for my needs) is the Nikon D3/D700. Or at least until the 1D Mk IV price drops..... ;-) And no, I have no interest in switching, so I'm not pushing Nikon, or even bashing Canon, for that matter. Just making observations....

3. Test charts: This is something I don't understand. While I get the need for standardized tests, the ISO test charts are 2D objects. When do I ever shoot anything that is 2D? Never! So why should I care about 2D performance? Yes, I know it can tell you how well a sensor / lens can resolve detail. That is ONE measure of performance. But my very unscientific real-world tests told me something far more important - when I need to get the shot, I have to work far harder with the 50D, and I get no real benefit in return (other than better ISO performance). Which brings me to point #4...

4. Why I did this: I have a limited budget. I see ads and reviews, and was feeling it may be time to get rid of my "lowly 8mp" camera that has been my go-to body for some time now. I looked at the 50D as an upgrade - double resolution, bigger screen, greater ISO, etc. A used 50D with battery grip is about the same price as a used 1D Mk II, so I felt it was a good comparison in my $$$ value-o-meter. I was keeping my 1Ds Mk II, so the full frame "studio camera" need was covered. In that environment, I almost never shoot higher than ISO 100, as I have total control over lighting. I wanted a better field camera. I wanted more resolution, as often I have to crop in tight for a shot, and found the 8mp sometimes lacking. Hence the appeal of the 50D and the 1.6x crop - greater reach on my existing lenses, and theoretically more resolution to work with. But I don't seem to be "getting the shots" with the 50D - even in controlled environments. I'm picky, and apparently spoiled, as the IQ of the 1-series is my benchmark. And apart from the ISO issue, I don't feel like the 50D is in any way an upgrade - for me. Other users may certainly disagree - and many will!

5. My conclusions: Unless you are at the very top end of the equipment/$$ spectrum, the IQ of the older 1-series and the original 5D are better for everyday use. For example, in the world of real $$, for the price of a 7D I'd rather have a 5D and a 40D. The IQ on these bodies are still excellent, and their ISO performance still falls well within the range I need (I rarely shoot beyond ISO 800-1600 ever). Two bodies with two good lenses covering a greater focal length gives you a greater chance to get the shot - until they make a 18-200 f/2.8 L IS with excellent sharpness at all focal lengths, controlled CA, minimal distortion and light fall-off, that is!

Technology and progress are great. The 5D Mk II is an awesome camera - no doubt! It is capable of producing some amazing images, given the right environment. But, as many 5DII owners know, its not the most reliable thing in the world. In a controlled environment, there's nothing that can beat it, short of medium-format. But I'm not always in a controlled environment - in fact, I rarely am - and I need to get the shot. So screw the ISO test charts - I need to know what works in my real world and in my real budget, and I found my answer.