Hi,
I haven't got the 200 F/4 but I do have the 165 f/2.8. From what I get, the 200 has several variations, the newest one being the best and closest focusing. I know that that edition was optically redesigned so it is worth getting the latest one if you go for the 200 f/4.
As for a lens I actually do have experience with, I personally think that the 165 is an excellent portrait lens, and with that big f/2.8 aperture its a magnificent piece of optical glass in my opinion. Really stunning with a nice circular diaphragm that stops down nicely and has really good bokeh wide open. I guess you could wish the 165 had a f/32 stop, which the 200 has, but honestly I never felt like I needed it. I have very little experience using the lens in landscape situations as I tend to use wide angles, but nevertheless I offer high praise for the 165, as I would for any P67 optic.