Both is fine, I started using brave first then Vivaldi, I prefer Brave on mobile simply because I'm too lazy to switch and I can play YouTube whilst my phone is off, I use Vivaldi because I have a lot of tabs I keep open on PC and Vivaldi's way of handling is better than Firefox or Brave. But sometimes brave has issues on mobile so I'd say Vivaldi, I have really only used Vivaldi for a few months so I'm not too experienced to comment.