FF does not support vertical tabs, extension makers try to
> "the killer feature that Firefox does better than most Chrome-based browsers is vertical tabs"
I find it hard to believe that this article first makes *this* particular claim, given that the Mozilla crew has all but ignored pleas for native support for the feature (while many of the Chromium-based offers have baked this right in at this point), and then goes on to provide a rather involved how-to (that is not for the weak of heart) on the tweaks necessary to semi-smoothly try to pull this off in FF (which goes way beyond just adding one of the many extensions). You lost credibility for this reader, sorry.
TBH, the *lack* of this feature, and the apparent disregard for users who have been asking for it for a long while now, is the number one reason I stopped using Firefox as my primary browser. I like many other things about it, but all weirdness was just getting to be too much.