Hello,
I can let you know a little about my experiences with my Leica 006, S100, SC120, S180 and S70.
I use my HC50 II for a wide lens.
The S100 can make a people shooter very, very happy. Just stop it down a little and it will give you sharp focus and enough DoF to cover your subjects face. Focus rolls off in a very soft way, but the lens (depending on lighting) has very good contrast and renders OOF backgrounds very well.
The CS120 is slower to focus but is razor sharp, it too can be used wide open. Having a CS lens is important but I have a full set of Hasselblad lenses and an adapter (full function on Leica S).
I can go on and on but Im running out of time. Look here for my cover and story
http://issuu.com/dailyfrontrow/docs/dailysummer_07142015 to see images. The shoot was a full day and it was all shot with the Leica S.
Cover and pages 55 to 72. I hope this helps you. Personally I want all of the lenses.