Attached are two (1meg) JPEGS taken with a ZD back in western Oklahoma this week end. I have had the back for about one week and so far I am mildly impressed. I purchased the back for landscape work and some studio. My normal use is Nikon D2X and Mamiya 645 film. I have not seen evidence of the (purple worms). I also have shot with all ISO settings up to 200 and don't see the noise some people are talking about. The back demands that the exposure be correct. It likes exposure as far right as you can with out clipping highlights.
The two attached files are jpegs shot in raw and converted with CS3 with little work done to them. One file is asa50 and the other is asa200 both F11.
I think they compare very well.