Sideberry does *not* solve this.1) It still has the horizontal tab-bar at the top wasting precious vertical space2) It requires trust in a third-party developer - now and forever3) It is relatively slow, and occasionally unstableWhat we should get is...
This is literally the one feature keeping me from using Firefox daily, so I'm excited to hear it's finally on the way. Once you've gone vertical there's no going back, and the extensions have just not been stable or good enough. So a native implement...
