I tried Vivaldi a few days ago as Firefox, despite their efforts to up performance, is still far too slow for me. The disadvantage I found that Vivaldi has is the number of extensions is basically 0 (please correct me if I am wrong). Installing chrome extensions is possible if you build from source and bake in the extensions, which is not something I am interested in.

I currently use Opera, but I am unsure about the privacy. Opera works very well though and there is an extension that allows installing chrome-extensions which works out very well.

Any thoughts on Opera's privacy?