Edge for me, since it has the single best implementation of vertical tabs on the market, with smooth expand on hover. Every time I try other browsers, I am immediately put off by how lacking in polish vertical tabs feel in comparison and go back.
As someone who loves vertical tabs, I was disappointed with Vivaldi's vertical tab behavior/implementation compared to Edge and Brave. I used Vivaldi full time for half a year before deciding to revert back to Edge for work and Brave for personal.
Of course you can customize with CSS and other types of things, but I'd ideally like my browser to just work well and be designed well.
Having said that, I miss some features from Vivaldi. However, I am much happier using vertical tabs in other browsers that have that feature.
Pretty happy with it; I tried basically all browsers out there, fully switching to them for some time even if I didn't even like them, and after all that time I found Vivaldi the best overall browser right now (for me).
Vivaldi is clunky and slow because the entire user interface (tab bar, address bar, title bar if enabled, etc) is a webview rather than native-ish controls like all other browsers.
I used it for six months and it had some things I really liked about it, but there were some really frustrating bugs that would pop up each release. I eventually got tired of it and had to move to another browser.
It's a shame, because I like the attitude and spirit behind Vivaldi.
Firefox's new implementation is subpar. You're better off using an add-on like Sidebery for more features, but you need custom user chrome CSS to hide the horizontal tabs.
I really don't see many similarities between Orion and Arc but I also didn't use Arc very much because I was pessimistic that it would stay free and consistently updated without annoying monetization features. I didn't expect them to switch to a brand new browser though lol.
