I'm glad there's something. Chrome simply sucks[1]. Firefox is complicated[1], and even if you invest time, there are too many things wrong[1]. There's not much else (as in different). I tried Vivaldi many times over the last year, and my conclusion is that I find it unusably slow. They take direction I like, but they chose technology that is bad (but cheap). Maybe it will get better, I surely hope so. Another nitpic…
I'm used to all these little features of the native interface and if you remove them, my productivity suffers.
Also, no MDI. Although at least the devs did a good job including the "click current tab to go to previous tab" option. 80% of my use of MDI in classic Opera was to do that.