Hey Mike, Bill
I've had my 10D for about as long and it has served me well both photographically and financially, easily paying for itself after my 1st commercial shoot with it. As Karl said, a lot depends on the Aboriginal American (being PC here) v.s. the pretensioned wooden projectile hurling device!
I was very determined not to go the 5D path and even passed on the 30D (I was in the top 5 for the waitlist on both cameras with Allen's Camera)
I was very happy with my 10D until my Sulu Sea trip when one of the guys handed me his Aquatica housed 5D with the EF15mm FE. The resulting images ... http://wetpixel.com/forums/index.php?showt...5&hl=5d+sunball
...simply blew me away. An "Actual Pixel" zoom of the image will let me count the individual coral polyps on the whips. There was no cyan fringing whatesoever on the sunball, something that happens with greater frequency on the 10D than not. That coupled with the near instant startup as opposed to the 10D's 3-4 sec has made me a buyer. It did help that Canon offered a $300 rebate for the 5D as well as an upcoming catalog shoot.
I'm keeping my 10D as a backup camera, it still produces beautiful images and likely for super macro applications, I'll use it instead of the 5D....
I never bought into the EF-S line since the 10D doesn't support it anyway.
Stu ;D