And now my first feedback
Hello, my opinion is based on the current snapshot 18.104.22.168 for 64bit (Win7 64bit). After I have figured out how to use adblock here, I was switching vivaldi to my defaultbrowser. Many things I like were already in and is working very well. Like stacking tabs, side panel or the permanent searchbar. The browser is very stable and fast for the current state of development. I was using Opera since 5.0 and was really disappointed with the version 15 like many old opera fans. My problem was not the change of the engine, it was the lack of old features. Now I am waiting for getting better extension management and customizble designs. Oh, and I want also to use search in page with the right searchbar . I know there is still a lot of work to do, but they were on the right way. Ok, that´s enough for my first 2 (euro)cents and sorry for my bad english, it is not my native language.
I'm still waiting for the "Open new tab" mouse gesture (usually: r-click, swipe down) before I can switch. I just use it compulsively, can't live without it.