@jon Vivaldi on android is the only one that does tabs right IMO with the tab bar.
Firefox is nice because it's one of the only ones not using chromium or WebKit and with, finally, vertical tabs I am pretty happy using it on desktop again.
And Vivaldi and Zen Browser because of the amazing split screen feature.
But I prefer Zens sidebar tabs and the fact its also based on Gecko.

So for me it's Zen and Firefox on Desktop and Vivaldi on Android.
Which makes me unable to use sync :/