I have been using my new zd for interior jobs the last weeks. Quite happy with it (apart from the frontfocus).
the dynamic range ist just great. no more overlying two 5D images to get a better range. (that was my main reason for the ZD). the colors and contrast are better to.
And you get that lovely 4x5kind of frame! (allthough my clients all seem to crop it down to a 35mm frame again :-(
has an enormous DR from the shadows to the window, there was no part of the image above 255. especialy the reflextions from the window on the floor were keept nicely. with the 5D this would have been imposible and would have required two exposures (not such a big either).
But my feeling: if you intend to use the ZD handheld (perhaps to shoot people or other moving objects) I would stay with the 5D.
I see my 5d and zörk as my mediumformat substitute and the ZD as my new 4x5 (sadly without itīs shift ability).
The ZD has an impresive mirror/shutter slab - sounds great, much more professional ;-) then the 5D "clack" but you need the mirror-lock-up and the self timer or the remote MLU from the notebook/remote capture to get the resolution advantage.
anyway, if you want a file, let me know.