Vivaldi is exactly as slow or fast as any Chromium-based browser. A this point I've surrendered to the notion of the web never getting faster, but just eating away any efficiency gains in computing.
I like Vivaldi for the feature set. It's rich enough for the regular power-user, but the presentation is straightforward enough that you don't feel like you need to pimp your browser like you would Emacs. I felt home with Opera, and I feel home with Vivaldi now.
> Vivaldi is exactly as slow or fast as any Chromium-based browser.
That is not my experience at all. I tried a few different versions over the years (including the beta with the mail client, but not yet this 4.0) and the UI always feels ... slow, and not quite snappy enough to be comfterable. It's really hard to describe this and I'm not the kind of person who quickly gets annoyed by this sort of thing, but for me personally it's too much and every time I tried it it was annoying enough to give up after a day or two. It's like using some remote connection with X or vnc (okay, maybe not quite that bad, but definitely reminiscent of that).
In comparison, Chromium or Firefox doesn't have this at all on the same computer.
Maybe it's a Linux thing; I don't know. I can imagine it's not the highest priority for them. A lot of it seems in the UI layer (and not the rendering layer), which is vastly different from Chromium. I hope they will improve this at some point (and I'll try out this version, too) because outside of this Vivaldi looks pretty neat.
Try the same test with Vivaldi 3.7, 3.8 or 4.0...
They've optimized the browser interactions quite dramatically so it's much faster than the video shows. But... It's still slower than Chromium's UI.
Vivaldi UI got significantly faster exactly two times from product inception. First time was a random Taiwanese hacker reverse engineering it, noticing they were resizing _all background tabs_ every time you resized browser window, and sending them a patch https://github.com/WillyYu/vivaldi_1.7. The second time Vivaldi themselves speed up Tab open operation, and only this one operation. "tabs open twice as fast. increasing speed up to 2x" sounds impressive until you measure 400-500ms instead of previous 700-900ms, versus ~16ms in Chrome (one screen refresh).
I like Vivaldi for the feature set. It's rich enough for the regular power-user, but the presentation is straightforward enough that you don't feel like you need to pimp your browser like you would Emacs. I felt home with Opera, and I feel home with Vivaldi now.