I used the 500 series 'blads for many years, with the 'silver' 50, 80 amd 150. I rmember reading in the BJP that Norman Parkinson had refused a 'free' new 150 from the makers (I assume that to mean the black type) because it was too contrasty for shooting women. He should have known, so I believe it. The main drawback I found with the 150 was that it wasn't a 180; they didn't exist when I bought into the system. If there was another downside to the 'silver' 150 it was that I found it pretty poor for shooting into the light; the Nikkors, on the other hand, handled such situations without problems.
I'm surprised that the Pentax 67 gets such praise; I bought a new Mk 11 and it wasn't what I'd hoped at all, and I got rid of it before the ordered replacement screen arrived. I realised that shutter bounce wasn't something you could avoid as you can mirror slap. But then, I find some other troubles with the D200 and D700: there is no better screen system (for me) than the split image wedge and a grid combined. Sadly, even for the F series, Nikon only made that combination available for use with slow lenses. Crazy. As for the digi bodies above, I really don't know if the screens can even be changed somewhere. I've given up the fight and accepted that I have to make do with what comes in the box. In other words, I've come to believe that we pay much more and also get less choice within whatever we buy; yes, plenty of functions I'll never want to use, but not a lot that I do desire. Of course, were I into af that would be something else, but I don't like it at all, and find that in rotten available darkness (such as bars) I can focus perfectly well with manual lenses of the 1.8 variety as well as my longer 2.8s. It's just that a split-image system would be so much faster in use; it always was, even when my eyes were young and bloody good.
Rob C