I don't like the lack of customisability. I've been using Vivaldi for a long time now and nothing comes close to how customisable and feature-packed it is. Everything can be set up and tweaked exactly how I want. My version of Vivaldi would look, feel, and act entirely different to someone else's, because it does what I want, not the other way around.

Unfortunately, it's Chromium-based. But the developers have been working on its native ad blocker in case extensions are impacted. They're quite a brilliant bunch, so I'm hoping it all goes smooth. I really don't want to have to go back to Firefox if I can help it. I can't stand UX for the masses and these guys get it.