The main reason I like Vivaldi is because I can use a lot of the functionality which I could get in the old Opera (ver 12 and earlier).

The keyboard controls (especially the single key shortcuts) save a huge amount of time. An example would be to navigate across tabs, or close all the tabs on the right (or left) are a huge timesaver.

Additionally, viewing pages in the reader view (again with a single key shortcut) gets rid of all the unnecessary stuff on the web page.

People who remember the power of the old Opera browser should give this a shot.