I'm on an Alpha build now. They are really catching a lot of the small issues I had. I've ditched Opera 12.x for Vivaldi now. I think they've made it good enough to be a daily use browser for me (not my primary browser).

Next in line is a bit better support for extensions and I could make this my main browser.

I'm back to using the newest tech preview of Vivaldi for OS X.  Safari didn't last long.

Yeah, having support for Extensions would be nice.  I guess that is coming soon.  They are working on it very steadily.