I use my M for everything but sports and concerts. Although I have shot some small venue shows with it...It gets the most use as a daily carry and/or travel. I have an SL system and always have a very compact as well (for now the D-Lux 8) but the M has been my favorite system since I started shooting it 5 or 6 years ago.
I'm always trying to find a better smaller travel camera, went through all the Q's, some Fuji x100 series the Sony a7cR's and lastly my current D-lux 8...
But when I get back from travels and do the processing, the M shots always stand alone, my wife and kids almost always choose the m shots as their favorites too.
I'm pretty sure I know what it is..."The process" of shooting the M makes you think about the shot more. Although I always try to take my time with settings and scenes with my other bodies, something about seeing the whole scene while focussing through the RF adds an extra layer of goodness. (Maybe some extra time)
I will keep my m10-R forever, which is weird because I'm a total gear head.
Cheers!
I use my Ms for everything. My personal work and my pro work. I have been all M for a decade now. You all know what my personal work looks like and for my pro work I shoot portraits both formal and environmental, Annual reports, avertising, billboards, automotive, some fashion (runway mostly). When I shoot concert work I usually have a lot of access.
Heres some examples of my pro work. All shot with Ms.
I use my M for all things travel (business and personal) as well as street. I have now been shooting with my M cameras for 3 years and truly enjoy not only the range finder experience but determining distances on the lens and shooting from the hip. It challenges me to the point where I can't put it down until I master it.
For all other scenarios, I use m fuji X cameras and AF lenses which makes using the M so special to me.