I have made the switch back to the 5D since the sun has set (temporarily) on my need for a 1 series camera. It seems to me that there is a way to prevent accidental EC change with the QC dial via a custom setting but I can't seem to find the answer in the manual I have downloaded. With the N you could map it to a different button so as to avoid unintended EC changes.
Am I imagining things of is it possible?
(I will be interested to see how the 5D pairs with my 85 1.2 II)
Well, the way I do it is to disable the QC dial when not actively changing exposure comp by putting the on switch to the first ON position. You may already know about this, but I'm not familiar with the 1D-series on switch, so it may be different. I'm sure your 85/1.2 will be fantastic on the 5D.
Jim, I'm sure that your suggestion will work for the 5D but the 1D-series bodies separate the on-off switch from the Quick Control dial switch, plus they have a personal function to prevent the QC dial being used on its own to affect exposure control. Tweakability is one of the benefits of going to the higher models in the Canon range.
John, you're out of luck. The 5D is basically a 20D with bigger sensor and better AF, but no more customisations. It lacks personal functions and there is no custoim function or switch to do what you want. Plus the manual on page 92 indicates that using the power switch to disable the QC dial is the only way to prevent accidental application of exposure compensation.
Now if you'd paid three times as much to get a 1Ds2 then you wouldn't have this problem
Too bad because I could not see a perceptible difference in the images from my old 1DSMKII and my previous 5D. That was one of the main reasons I sold the 1DSMKII.