I just do
not see all that much difference between DSLR and Mirrorless systems.
One system is missing a mirror and has TV viewfinder.
One system has a mirror and a Reality viewfinder.
Both systems require lenses & settings.
So what is the big deal???
You simply pick the system which works best for your particular shooting needs.
The actual game-changing innovation was the Cellphone camera. Simply brilliant!! I use mine constantly. And the photos are as good as anything I got off my Coolpix 990 and D100 back in the early days.
On a recent trip back home I noted that in my own family
everyone just grabs for their Cellcam and snaps away when the usual family photo is called for of grand-kids, group events, visitors, etc.
Including me, the current owner of about 7 camera bodies (mix of DSLR & Mirrorless). Nobody even uses a little compact camera anymore. They don't want to mess about with cards and inability to transmit instantly. I GET THAT !!!!
DSLR vs. Mirrorless is not an issue.
Interchangeable lens systems versus Cellcam is the real divide.
IMHO. YMMV. And all the usual disclaimers.
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FWIW, here in the US there is still a very heavy preference for DSLRs. I couldn't tell you why. I just was at 3 of our national parks. Anyone seen shooting "seriously" - that is, not using a Cellcam - had either a Canon or a Nikon DSLR. I saw one Oly EMD type. No Sony. No compacts at all. Granted, this was a
very informal observation because I was a bit busy with my own work.
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I commend everyone for their most excellent discussion in this thread. These kinds of threads can veer off course. I LOVE NikonGear for being so cool !!!