There are a couple of annoying things with vimium which, I think, are general limitations for Firefox extensions, or browser addons in general: - it loads after the page, so if you mistakenly open a link, you have to wait until the page is fully loaded to close it with the extension, but you can always use the browser's integrated shortcut Ctrl+W. So far so good - Letters positions are not as accurate as let's say, qutebrowser, and sometimes when you open a link it's not the right one, even if the letter was indicating it. For a clear illustration of what I'm trying to say, try to browse stackoverflow and use the reviews queue. - When the page is saturated, letters start overlapping, you find yourself with one link hovered by 'A' and another 'AA' maybe a couple of links labelled: 'AB', 'AC', ... and in this situation it's impossible to select the link 'A', you have to do it with the mouse.