[fschifano]

...The AF cameras proposed will normally not focus manually very well. Manual focus screens can be installed, but a manual focus viewfinder system tends to be different form an AF one in any case.

For a lot cameras, what you say is true. I would even agree with you when it comes to the lower end Nikon autofocus film bodies. But even though the viewfinders of both the N90s and the F100 are a little lacking when compared to the viewfinders of the F2, and F3, they are still very good and better than the finders on some other manual focus only cameras. Focus confirmation works well under most conditions with these two bodies as well, so it's not a real problem.