Thank you for this forum on extensions to replace TBE in Firefox. TBE's feature set is definitely worth the performance hit it incurred, which was never really noticeable for me.
I have a couple of TBE features that I think weren't covered on your list and haven't been replaced yet. They are very minor features, I think, but I really liked them.
1. The ability to prevent the last open tab from closing. TBE had a feature where if there is only one tab open, it cannot be closed (even with "Close All Tabs"). This allows me to configure the browser in such a way that it forces the tab bar to always be present and to always have at least one tab. It keeps the GUI consistent, which I like.
Browser tweak: Set browser.tabs.extensions.last_tab_closing to 2 in about.config.
2. The ability to remove the "Close Tab" button that appears at the right end of the tab bar. I prefer each tab to have its own "Close Tab" X which makes the X at the end of the tab bar redundant. It's been suggested that the X in the tab bar is better suited to mean "Close All Tabs" rather than "Close Tab".
BTW, I installed Tabbrowser Extensions in Firefox 1.0PR and it seems to work fine. I got the extension from
http://white.sakura.ne.jp/~piro/xul/_ta ... ns.html.en
Thanks.