For comparison of the greyscale rendering I made a
testfile, and took pictures of two pages:
http://baach.de/Members/jhb/greys_times.jpg/view
http://baach.de/Members/jhb/greys_fontin.jpg/view
The greys that you see reflect reality quite good. The focus in the middle and bluryness on the outside is only in the pictures.
I assume that the difference you see could be compensated by software, but I am not 100% sure - could be the actual vizplex/pearl difference as well. Does anybody know?