I just wanted to come here and say, that this has become my favourite browser in all my 24 years of Internet use. Most of the time when I like something, I just don't complain about it but this needs to be said.
It has all the goodness of Chrome(ium) under the hood, without the dumbed down user interface. Vivaldi has admirable settings and configuration options, including some of the features I really liked about Opera. (for example the "speed dial" screen that actually lets YOU add your own tiles, instead of populating them with random, undesirable sites that I would constantly be X'ing out)
Also, thanks for using a somewhat older dev box for the Linux binaries, which makes them able to run even on my heavily customized Slackware system (which doesn't exactly have the most current libraries etc.). I am able to manually extract the deb and copy the business end to /opt/vivaldi, set the permissions for the sandbox and add /opt/vivaldi to my path. Performance is grand, and I actually have some hardware acceleration (unlike Firefox) using the AMD fglrx driver (as I would with Chromium).
My main platform is Linux, but I also use Vivaldi on my Windows 10 gaming rig, and also in a Windows 7 virtual machine that I do some work in. (VirtualBox on Linux). I am equally happy with it in those environments.
Appearance pleases me too, I don't have to do very much to that Dark Theme to fit in with my environment. (basically just the accent colour settings)
Anyway, thanks for the great browser. It puts the others to shame, in my not so humble opinion.