How does it do with tab reloads?
Vivaldi has started to slip for me in a few edge cases I don't have organized right now, but in general and it's becoming noticeable with Ludum Dare reviews, my machine isn't all that high end, (my brother may upgrade a chip or something for me next year), so just having stuff in diff browsers minimizes the damage.
My third is currently Chrome, which I am certainly no fan of, it just happens to be a thing. So I'm not interested right noew in all these payment widgets, but a (another?) Chome-esque engine with ... decent attempts at ad protection, is worth a look.
Bonus if there's an extension for a horozontal menu! (PRob is for Chrome but it's only third).
And then ... Tab reload. Firefox does a passable job with it. I haven't found the setting for it in Vivaldi yet. (Anyone know if there is one?) So besides my mediocre comp, LD games can sometimes have some coding errors, most of them innocent, that can just stall out the browser. Then I'd lose 20+ tabs!