I think there is a point you are missing :
Opera didn't need differentiators. Opera was different, from the ground up. Not only that, but it was also for different people.
I hate Chrome-Fx-IE-Safari, because they are a "one size fit all". Or maybe a "one size fit most". But I'm different, and I don't fit.
Maybe I have only one arm, and I want one key shortcuts. Or I'm blind, and I want connection with a screen reader. Or I can only read standing up in front of my fridge. Or I'm still running win98.
Opera was for the differents, for the outcasts.
It was so versatile, but also, installable everywhere.
Now, Opera shifted its paradigm. Now, I can't install Opera on my Android 2.3 device, or my Linux 32b desktop. I'm not blaming anyone, those changes make sense, and you (all) are doing a wonderful job given this market/ressources/time/money/politics.
But when I look around, I weep, because there is no alternative. Nothing for the differents, the outcasts. All I can see is some browsers, with a bit of differentiators. Yes Opera is still the best browser around today, but it's sad considering what is possible and what was.
I'm crossing my fingers (and my toes) and waiting for Vivaldi and Otter. But my hopes are not that up : it doesn't make a sens to do a browser that is different in this global market. And I weep.