well, I read all the advise and (with it all in mind) walked into the store. I decided to maybe hold off on the F3 for now and wait for a better one - ideally an HP.
I'm also going to try to get a better focusing screen for my FM2.
I walked out with a Nikon F801s!! Took the advice about the electronic rangefinder. Definitely useful. In brighter light, the viewfinder is pretty clear!