John A , Apr 05, 2011; 10:31 a.m.
Having had--and still having the 7--these cameras I would suggest a third option to consider--the RB instead of the RZ. Mostly because the RB is all mechanical and so you don't rely on a battery--which always seemed to go dead on the RZ. If that happens, you only have 1/400th of a second shutter speed, so the RB is really a much better field camera IMO as you never have to worry about it.
Consider that the 7ii has a meter built into it and you would have to have a handheld meter with the RB/RZ's, which isn't a bad thing, just another consideration. The ergonomics on the 7ii are very good for a rangefinder, I have had others that were great cameras but very difficult to focus and manipulate, the 7 is a good one in this regard. My favorite lens was always the 65mm, which could be a bit short for head to waist shots, but still workable. The parallax is the issue with a rangefinder and the closer you get to a subject the more of an issue it becomes.
The advantage of the RB/RZ systems is probably going to be that they are less expensive and a bit more flexible as to shooting, although beasts to carry. The SLR and rotating backs will make your life a lot easier while the weight might make you a lot stronger over time. Personally, I like the SLR feature for those things you mention you like to do(although having no large mirror to pop out of the way, makes it much more responsive to capturing that momentary expression) and although I have carried my m7 around a bit over the years, it was never really used too much as I preferred having the slr feature. But I was very good with external meters having shot mostly LF for 30+ years. It isn't an easy choice if you don't have experience with either, but there probably isn't a bad one but maybe just an interim one.
(I also liked the 65mm a lot on the RB and Rz's--the RZ body can use the RB lenses, which is how I used them since I had a full set when I got the RZ bodies--I shot as a pro, so I had a full set of lenses and only changed for a very specific need with one major client and wished I hadn't)