Love my 40D, have used the hell out of it since 2007. I would possibly say the step from 350D to 40D was more significant than the step from 40D to 5D2 (which I only made last week after canceling pre-orders on the "3" and D800).
One of these is a 40D. One is a 5D2. Both are the EF50mm f/1.4. Without pixel peeping (or EXIF cheating), I would be hard pressed to tell which was which.
I would say the first is the 5DII
I had to find a couple frames where the shallower DOF of the 5D2 with closer framing didn't give it away
5D2 facilitates higher sensitivities which is great for around the house, and framing on the larger format is certainly nicer for people, but otherwise at internet res and in print the IQ is pretty similar.
(40D image = 100ISO, 5D2 image = 1600ISO; I dread going over 400 with the 40D if there are any deep shadows in the exposure)