My thoughts and feature requests
Vivaldi has been a decent experience so far, basically Opera on a webkit/khtml chromium backend. I've used browsers since their earliest of versions Mozilla 1.0 (not firefox at this point), Opera 5, Google Chrome 1, and before all of this Internet Explorer 3.0
Vivaldi, and Opera for that matter, have always been refreshing and while they're packed with usability features I always find that there's something missing. For example, tags with bookmarks. Sometimes folders just don't have the ability to organize as you need. Being able to filter bookmarks based on folders or tags would be amazing. A lot of times I'm researching something for my next project and I'd add a bookmark to a specific folder; but then I'm working on another project and remember this page I visited 10 months ago but can't seem to filter it out with the 10k+ bookmarks I have.
A lot of times I bookmark things in Firefox for this functionality .
The ability to take notes on pages is awesome. There's plugins to do this on other browsers but I enjoy features like those being baked directly into the browser. The notes and bookmarks features need to be more correlated. When I open a bookmarked page it should be able to show me notes that were taken on the page, maybe even highlighted sections that I was interested in and some on page notes that can help me remember what I was thinking at the time. Furthermore, when I do open a bookmarked page that had notes, it should tell me.
Of course I'm just yada yadaering over here and I understand there's much more important features to be fixed/included. This is just my 2cents.
@mumblefysh Regarding your feature request - there is a thread to post feature requests and upvote already made suggestions to bring more weight to those ideas. In your case the bookmark tagging system was already requested.
You can find the feature request thread here: https://forum.vivaldi.net/topic/20037/feature-requests-for-1-12?page=1