The problem is that with such a long list of tags, I can't always remember if I tag something "manual" or "handbook," so it's nice to filter by notebook, then by tag. Shift-Alt-T works, but there is an extra click. Instead of click notebook>scroll down tag list, it's click notebook>shift-alt-tag>scroll down notebook. Tag hierarchies are also handy, which you don't get in the flat pop-up list. The focus needs to be on the note or note list as well, so sometimes it's first click on the note, then shift-alt-t. The popup lists populate slowly, and with one of my notebooks, it brings up the wrong tag list.