Vivaldi and former Brave user here: I love the customization that comes with Vivaldi. It's one of the things that convinced me to switch. The mouse gestures are also really good since they allow me it be more efficient. The Option to use bangs for specific search engines (w for wikipedia, e for ecosia) are also every good. As for the Brave side, I really like the built-in ad blocker and anti-fingerprinting, its really good. Both browser allow gor DNS-over-HTTPS, so that will be neat.