Old school request
I know it's old school and goes against modern UIs, but in Opera I used to have pages open in MDI windows instead of tabs. I find it useful to be able to open two or more pages side-by-side for comparison, and it's convenient for them to be within the same instance of the browser (only one app to minimise/find on the task bar).
Try selecting two tabs with Ctrl + Click, then Tile Selection from the right-click menu.
Excellent. Didn't know about that one. It's not quite what I wanted, but I can live with it.
You can also add a frequently used site as webpanel to have the movable divider.
I agree with PhilRogers: real MDI implementation would be fantastic.
"Tile selection" is cool but it's a poor substitute for real MDI windows.
I want to have multiple windows and arrange them freely. I want to be able to build my dashboard with all the pages I want to deal with at a glances! Wide screens must be used for what they allow.
MDI is a unique feature of Opera (up to v12) and would be a real disruptive "innovation" from Vivaldi. What a buzz is could be!