@jon Firefox on Desktop, Vivaldi on mobile.

Vivaldi is close for me on Mobile because it works really well, but I'm using the Fennec version of Firefox from F-droid currently and it's a favorite, with Vivaldi close behind. Close on mobile because it's the second closest thing for me on privacy goals, and Firefox & forks on Android are a bit buggy.

Firefox (preferably forks) on desktop fully because of the UI being open source, no slight against Vivaldi for that, I fully understand the reasoning for not doing so. I just prefer open source so I bias towards as much as possible of it when not overly difficult to do so.

I do not trust Mozilla, more open source nature of the app allows me to take trust of ownership out of the equation a bit, especially so with forks.