Vivaldi is not bad, but in folder view, it's all white and not very plain. You see neither thumbnails or icons. And the theme possibilities for wallpaper are very limited. Still nothing/white for the folder is a big improvenent over the garish icons. Of course, Vivaldi is in a state of becoming, so that could well get better. I prefer not to set up folders in the speed dial, but rather use speed dial pages. You can use multiple pages for the Speed Dial in Vivaldi (something you can't do in Opera).
The SuperStart speed dial extension in Firefox is really good. It gives you folders for your speed dial positions, thumbnails for your icons, and the wallpaper looks terrific on it. Also if the icon folder, blocks out part of your wallpaper, you can put a blank placeholder in that spot, so you can see the wallpaper where you want to. (That's a nice feature Opera never had). The extension takes a little fiddling to get used to it, but is worth it.
