Sigh... No, Mozilla, this is not what we wanted. We already have 500 sidebar tab extensions. We wanted horizontal tab groupings. It's not that unreasonable. I've been following this issue for 3 years now and this is what they cough out? I'm over it. I'm moving on. So frustrating.
Counterpoint - I wanted a native implementation of vertical tabs. Sidebery's fine, but it feels like an extension rather than something properly built in.
