Vivaldi is on par with the best browsers and beats everything on aesthetics if you don't mind a highly styled interface, so why not?
I would swear the latest version I could get to run in Tahr was 1.9 (which is still above-average compatible), but there's a 3-era standalone out there which runs too.
What else is there? Performance. Compatibility. System resources.
I was imagining an older browser is going to be lighter and more efficient, but as new pages are 'looking' for new browsers, compatibility with new browsers is going to mean better performance.
Security and performance are going to be a confluence of a factors that are not hard and fast conventions.
I've gotten excellent performance recently in Firefox on Ubuntu 64, so Mozilla isn't the problem. In Puppy 32 world I was believing Chromium is best for benchmark results.
I can't really talk shop because I don't settle on a browser. One's for news and social networking, another is for commerce, a third is for education & research, etc.
If Vivaldi will maintain 32 more power to it. I would be happy there or on Iron. I suspect more will be dropping by the wayside until we're left with only a couple choices.