Tree Style Tabs has more features and is arguably better. In the year following the core changes in Firefox (Chrome extensions, threaded tabs) I had many bugs (

Tree Style Tabs has more features and is arguably better. In the year following the core changes in Firefox (Chrome extensions, threaded tabs) I had many bugs (high cpu load, broken tree, no restoring at startup...) but I haven't seen a bug in the past year. Configuration was not easy though, and It don't know if it still requires fidgeting with Firefox's files in order to remove the default tab bar.