Now that ergonomics has been brought up, that is the one thing that I found so difficult about using the M3 and the Canon for that matter too.
The bodies are well made, no question there, but they don't lend themselves to being held in the hand very easily if you ask me. First off they're very 'solid', ie a little weighty, and second I found they're skinny with no 'grip' on them. Once I found a grip for the M3 I found I could actually hold the camera a little more easily.