Body, 90% of whether I get on with a camera or not is to do with the body ergonomics, if they're bad, it doesn't matter how good the lenses are.
If I can't get comfortable with it, I can't produce anything good.
I have a Yashica Minister D, the act of checking the meter then transferring the information across to the lens, breaks my flow, and I produce rubbish with it (and I've usually left the lens cap on for some of the roll too).
In general with Rangefinders, I have a habit of turning the camera to portrait orientation, then blocking the windows with my focusing hand, among other things this is why I've come to the conclusion that rangefinders and I are not an ideal match at this moment.
With my SLR's they do what I expect them to (hopefully), and I don't get in my own way as much.