I really tried to like Vivaldi, and it could be a good browser, but is so unbearably slow. The whole UI is unresponsive. Opening a new tab can take almost a second. Price for javascript apps I guess.
edit for clarification: This was on OSX, on Windows it was OK.
Used it for almost a year as a secondary browser, no change, gave up.
I found a bug that slowed it down a great deal. It was the fact that they put multiple `filter` styles onto the tabs, even when those filters did nothing useful. It was still extremely taxing on the GPU driver.
But, since you can customize the UI with your own CSS (there's a hidden setting you need to enable first, in vivaldi://experiments), I put a simple `* {filter: none !important}` in there. After I did, it felt as if I bought a new computer.
The fun part? They still haven't acknowledged it. Even after I gave them the exact steps to fix it.
I just did some tests and was unable to replicate your results. I'm on an i5 2019 Mac, and Vivaldi takes about 200ms to open a tab, with or without CSS filters. (200ms is bearable, but it is slower than I would like.) I have Hardware Acceleration on and Use Animation off.
I'm not sure about the internals, but when those filters are there, the GPU process causes a lot of CPU load on every frame. So much that it often hits 100% of the single core it uses before it's able to draw at 60 fps. Oh and it redraws the tab bar a lot. It redraws it every time you scroll a page, and it continuously redraws it when there's a tab playing audio in order to animate those waves emanating from the speaker icon. Yes, it redraws the entire tab bar for a 16x16 animated icon.
They unfortunately don't have a public bug tracker.
Do you have an older machine, or is it even slow on new machines?
I tried Vivaldi last year on my computer which is about ten years old now. Vivaldi was extremely sluggish (Chrome
and Firefox still run fine), I was hoping to come back to it once I upgrade my computer.
My experience with an 10 years old computer with win 7 is that firefox is slow and vivaldi is faster. I don't use chrome. On Android vivaldi is much faster than firefox.
After the 3.7 release they've improved UI responsiveness quite dramatically. In my laptop (i5, 8200U), opening a new tab or settings used to take 1 to 2 seconds, but now it hovers around 250~300ms.
It is indeed bloated. Its main redeeming quality in my opinion was that it was the only chromium-based browser that allowed sideloading extensions freely, but now that's gone too since Chrome and Brave have apparently started allowing it as well.
Odd because the one thing I remember about Opera from back in the day was how fast it was. This was back when Firefox was king amongst in-the-know users but IE6 was most popular overall. Opera was so much faster and smoother than everything else.
Opera was fast and stable, especially with more tabs open. Way into the Chrome era too. Too bad Google used it's monopoly to drive other browsers to death. Only Firefox survived really.
But not that much for a new/mail reader -- even 100% native Mailmate sweats with my 50k message GMail archive. While it may work for casual users, I'm not really that convinced it is the killer feature Vivaldi users are expecting.
edit for clarification: This was on OSX, on Windows it was OK.
Used it for almost a year as a secondary browser, no change, gave up.