I work with Leica M digital for both my professional work and my personal work. 2-M 10s, an M 262 and an M-E for color and an MM for B&W.
I use the equipment I use because it fits the way I see and work. Maybe I am kinda like Bill and maybe a little mussel memory? I don't have to think about the function of hte camera when I pick up my Ms. That part is just second nature after over 40 years. I just love the way they feel in my hands and the way they function. I don't like a lot of automation.
When I went digital in 2005 (had to because of clients) I left film kicking and screaming (plus a divorce, downsizing and other circumstances left me without a darkroom) Leica didn't have a full frame digital option or I probably would have gone Leica instead of Canon in 05.
I still have a couple of my old F-1s and a new F-1 and love those but I dreaded using my Canon digital cameras because of the way they function. For me they were not intuitive to use no mater how hard tried. I had them for over a decade and never warmed up to them.
I picked up an MM in 2012 after using a good friends M9 on a trip to the Fla Keys and Key West. Fell in love with the camera so I picked up the MM for my personal work. Liked that experience so mush when Leica introduced the M 262 I bought one, picked up an M-E for back up and sold all the Canon gear. That was almost 4 years ago.
Picked up an M 10 when they first came out and then another M 10 last year. NO REGRETS. I do not miss the Canon gear at all. I really thought I would miss longer lenses like the 200 2L. I don't.