I've used Opera for a long and I must say that I'm quite enjoying Vivaldi so far. That being said, I just have a few comments about it. The only two bugs or glitches that I've noticed so far is that it takes me a few clicks of the shortcut to launch shortly after start up, the other is that a new tab gets offset onto a neighboring tab every once in a while. I absolutely love being able to stack multiple tabs under one tab, although sometimes the miniature image of the page under the tab is the wrong image. I would most like to be able to right click + open a new tab directly into the stack of tabs I'm already working in, please let me know if this is possible and I just haven't figured it out yet. Aside from those minor things, I'm very much enjoying the browser, keep up the good work!