Rated 4 out of 5 stars
I have been using this add-ons for years and it's probably the main reason why I'm still using Firefox.
However with the new update on Firefox 29, I really miss the double-click on empty area opening up a new tab... please bring it back!
Edit: Thanks alot for the reply, appreciated, I realized that after I went back to Firefox 28 which seems to suit me better for now than the new 29. Cheers.
It's not a feature of TST
The feature you said ("double-click on empty area opening up a new tab") is not a feature of TST but Firefox's. Now Firefox doesn't provide the feature anymore so you have to install any other addon provides it. (I have no plan to add it to TST because it is not a "tree" related feature.)