Justin - you seem like the guy who hunts A LOT and in all kinds of weather. I researched the leupy a lot and finally got my hands on one as did my brother (mine was 1000i and bro was 650i). They worked fine and after hunting one day in the rain, total was about .82" for the day and we hunted out all day, they got fogged up inside and BOTH stopped working. They had water inside the unit. I had mine with the lanyard around my neck and the unit was zipped inside my chest pocket of my Chugach Nx and my bro had his sitting in a crooked horn bino system rangefinder holder under his Chugach Nx jacket (however he glassed in the rain more then I did).
After that I looked up their warranty and saw that they actually claim the rangefinder will hold up to rain while being a pocket (their exact wording, lol) but the unit is NOT waterproof nor IMO will it hold up to any amounts of rain.
This was something I had never, ever read from any review about the leupy. I am not sure if guys don't hunt with bows in the rain or hide the rangefinder from the weather or what.
I have never used a Leica.