I've owned the 85 f/2. If you want a very lightweight lens in the camera bag it is a joy. You'll have to go up a paper contrast grade when printing B&W.
I've owned the 105 f/2.5. Great lens, with a longer "social" distance from the subject.
I now own the 85 f/1.4 AF (77-mm filter). It is a boat anchor, but the extra stop and the better glass is very worth it for extreme situations.
If weight is your concern, I pick the 105 over the 85 f/2, because it is a superior lens.
If weight and money isn't a concern, the 85 f/1.4 is a winner.
Personally, nothing beats my 75-mm f/1.4 Summilux-M. If you like rangefinder systems.