Main thing I want from a tab manager is for it to auto-save sessions so they can be restored when Firefox inevitably fails to reload them after a restart. This does not appear to do that. It appears to do nothing but facilitate navigating between tabs, & suspending some tabs that are not currently needed. It seems to do those things OK, but they just aren't nearly as important to me as the baseline functionality of saving a list of open tabs to be restored on restart.