Neat! I'm not the grandparent poster, but I also can't stand horizontal tabs, probably because I'm a tab hoarder. But with screens wider than they are tall, vertical tabs make sense, and each new tab doesn't truncate all other tabs' titles.
I looked up MS Edge's implementation, it seems it only shows the tabs either on top or on the left of the window, with Vivaldi you can set it at any edge of the window, I have mine on the right side.
Indeed, for least distraction, content should start at the top left of the screen. For this, I already had my tabs on the right, but now I am trying bookmarks/address bar at the bottom.
Not sure I'll keep it this way ... but what I ♥ about Vivaldi is the choice. If I wanted training wheels, I would already be using macOS.
The last update was made in 2018. That's a long time. It would be nice to revisit this now that they've have added more services (Mail, translations, expanded Sync) and see their impact to the browser's privacy.
