I like the overall concept of Vivaldi with all the customisation options, but it's unfortunately a buggy browser. Many sites that work fine in Chrome and Safari don't work properly in Vivaldi. Also, from time to time, Vivaldi will crash with a segmentation fault. Vivaldi uses the Chromium engine under the hood, but they are using it in a way that, for example, breaks YouTube on macOS. Random pages, usually obscure ones like an email unsubscribe form, malfunction. I really want the tabs, though.