Summary: I find I don't take the M6 out of the house that often. I feel like it's an expensive unit ... I don't want anything to happen to it. As a result, I've only run maybe 6 rolls of film through it in the past year.
The Zeiss, by comparison, is a bit smaller and lighter. I appreciate the electronic metering and bigger VF. Plus, this particular body is a real road-warrior. I don't care if it gets bumped or knocked around a bit.