Firefox is slow as molasses for me, Chrome-based browsers feel SO MUCH snappier - I'm talking about things like e.g. tab-detaching.

I moved fully to Vivaldi about half a year ago and I couldn't be happier. There are only 2 issues I've encountered so far:

- sometimes, video in full screen is flickering (known issue) - sometimes, when the tab is closed while playing video in full screen, the whole browser UI disappears and the only way to fix this is to kill and restart the browser - the obvious workaround is to never close the tab while being in full screen

Other than that I'm very impressed with Vivaldi. Gestures, clean and USABLE interface, web panels are great features that I can hardly work without anymore.