NickSimcheck wrote in post #3890714
Since everybody is trying to see how the image quality is on the 40D and even compairing it to the 5D, I feel the need to state why I still liked my 5D a lot more.
Ergonomics. The buttons, thier feel and spacing the thumbwheel size and placement, all of it was just
better on the 5D.
Viewfinder. the 40D is a good viewfinder, but full frame is just awesome.
Weight. The 40D is too light with heavy lenses attached. A 5D with BG-E4 and a 70-200mm f/2.8 IS was balanced perfectly and even though it was heavy it was very controlable.
Thumbwheel. I know I already mentioned it, but it's a HUGE difference and the 5D's was larger and placed closer to my thumb and was just soo much better to operate. This is my main gripe about the 40D.
Those are the biggest differences I can see.
I am bored so going to reply to this
1/ Ergonomics, it is everyone to their own, but if you have driven an Automatic car, and a manual car the difference is massive at first, drive both regular, it is like a 2nd nature, you pick one up and shoot no probs and vice versa
2/ Viewfinder, VF on a 40D is an improvement for sure over all other 1-6's, but as you state FF getting on for £1k more for body, I would like to think it is better. Never looked through a 5D, but Like you and many others I believe you
3/ Weight. you compare the 5D with a grip, I take it you are not putting a grip on a 40D I don't find a lot wrong with my 40D with a grip on it, except with a 70-200 2.8, 40D and Grip with 2 battery's, it is damm heavy 
4/ Thumbwheel, I like the Thumbwheel on 40D anyhow see 1/
5D is a great camera so everyone says, I don't disagree, 40D is a great camera for price and fair big jump on all other 1-6's,
heh you should get both, quite a combo, pretend the 40D is a sporty manual you need to learn to drive differently, and use for the thrash around on sunny weekends on the open fields, and the 5D is an auto, lovely, smooth and relaxing go anywhere sort of body 