I am coming to the camera's defense here for a moment. I have used my Leica (an M8) in countless snowstorm situations shooting landscapes and I regularly drag it out in the weather to shoot all kinds of images. I've also used it many times as a portrait camera and I LOVE the results and don't find it hard to focus. It's a skill you must get used to with the camera. In fact, I find it can be quicker then my former Nikon DSLR and I TRUST it far more.
Although I have made money with them, I never felt comfortable with any of the DSLRs, but the Leica gives me "comfort" and confidence it will produce. I fact, I recently sold ALL my DSLR equipment to concentrate on my Leica system. I know another guy who shoots for the AP with an M9 and last time I saw him use it, he was shooting in 5 degree weather here in Vermont and it WAS snowing.
The Leica rangefinder system can be "quirky" but I, like many of its devotees, I feel that once you "master" it, the camera captures "your vision" like no other camera can. NO camera is perfect for every situation, and I often say "it does not matter what camera you use" when young people ask me, just use one if you want to.
Different cameras work "better" for different people but to say the Leica M9 is not a professional camera is pure Vermont cow shit. I'm a professional and I use them.
My friends know I love me some Leica M8. I foresee using a Leica M8/9/ME/? as long as I am able. It is my camera and lens system of choice. I regularly use lenses that are 30-50 years old on my Leica body and the results are outstanding (try that Nikon, Canon, etc etc). There is a feel and rendition like no other camera system can produce.
The Leica M9/8/M/ME system is pure professional grade and to me, one of, if not the best system there is. Period.