I had a leica m9 with me for a week with a summilux 35.
I had fun, I think. Rangefinder was interesting but I think it's as you say, you need time with that camera and lens system to really get into.
Gear isn't everything ;P I prefer my xt-1 pics that I took at the same time.. and I do like manual focus (for portrait) even with my xt-1 so it's not even that!
If I had the money, I would probably go somewhere else than Leica (Hassel, pentax).
This is prolly my fav shot...