What a great browser!
I first installed Vivaldi on Vector Linux (version 7.2 RC2 beta) a few days ago, and have since also installed it on Lubuntu 17.04, on an old notebook computer, and in Linux Mint 18.1 on a newer (2009) notebook. I haven't tried it on Windows 10 yet, but I will, shortly.
I have to say: Jon and the Vivaldi team have created a superb browser, with cutting-edge, useful features for us power users and Webophiles. Congratulations to them and kudos to their efforts to bring us this browser!
I am a convert- I don't see any reason to continue using Firefox, Edge, Chrome, or any other browser, other than possibly on old hardware. On an old (circa 2003) emachines M6809 notebook computer, I have installed a few Linux distros- Lubuntu and two versions of Vector Linux. That machine has fairly low-powered CPU and RAM (AMD Mobile Athlon 64 and 1.25 GiB RAM), so I have to use the lightest OS and system components available, for the system to remain responsive. On that system, I can open four or five tabs in Vivaldi before things start bogging down.
On my 2009 notebook, a Clevo M570TU, I have installed Vivaldi on Linux Mint 18.1, and it runs great! This system is not so CPU and memory-constrained as the emachines- an Intel Core 2 Quad Q9000 CPU (2000 MHz x4) and 8 GB RAM. I have run about 16 tabs in Vivaldi, and System Monitor shows about 48% memory and 20% on CPU usage.
I have an even newer system, a 2016 MSI GT72 6QD laptop with 16 GB RAM- I haven't installed Vivaldi on it yet, but I will soon. I have no doubt that it will run very well on that system.
Thanks again to the Vivaldi team for making such a great browser available to us.
@Doug54 Welcome to the Forums, and welcome to Vivaldi!