Oh man I am so bummed!
It took me some time to get the hang of working with RAW files. But since then I have realized that there is a significant difference both in image quality as shot, and more to the point in the images flexibility in post processing when compared to jpegs.
Despite this understanding, I have a tendancy to shoot jpeg with my 10D "when it doesn't matter"
In this case I was in a salt marsh,. no birds in sight,. so I mounted my 17-40mm "L" to take some fall foliage shots and mostly to get more used to working the circular polarizer in various circumstances.
In essence,. in my mind these were "test shots" so I was shooting jpeg. ("saving" card space)
Well,. along comes a Great Blue Heron,.. I swap the 17-40 for the 500mm f/4.5 (which is allready right next to me mounted on the tripod) and manage to take the most amazing "heron in flight" images I have ever taken. I was in the perfect place at the perfect time and was even given enough time to mount the perfect lens before the Heron took it's sweeping flight directly in front of me.
I could just die!
The large fine jepg images don't even come CLOSE to what this lens can do on the 10D when shooting raw! 
In essence despite the fact that I "got the pcis" and made NO mistakes with exposure... shutter speed (in fact the light was so perfect I was able to get these action shots at a remarkable ISO 200 (which would also have made these the lowest ISO action shots I have taken succesfully)
But despite hours of tweeking in PS the images do not compare at all to the images i took moments later once the heron landed and I had time to remember to switch back to RAW. No other settings on the camera changed, nor the subject,.. but the jpegs are poop in comparison.
Sure there may be times when jpeg is fine,. i have allways felt that. And it took me some time to get used to working with RAW files (plus I needed to get better tools like the Adobe RAW plugin)
...but now I have learned a hard lesson 
The folks who preach RAW on this forum know what they are talking about. Now I have my own side by side images to prove it to my own self. The difference is HUGE! and I have about 6 of the best photos I have ever taken ruined as jpegs to prove it. 



