So far the best replacement for the old tabgroup plugin by far. I recently just downloaded this and trying out, but I'm really impressed. Love the memory saving settings when you got tons of tabs in different groups. Will come back if I find some bugs, problems or suggestions!

EDIT: So a couple of things I noticed:
When trying to open a group as a new window does not work, sometimes it just opens a new blank page. It would also be nice if there was an option to take an already open window with tabs and create a group from that, rather than just one tab at the time. I don't know if it's documentet somewhere if there is a way.
When clicking or hover over the Tool tips (?) does not seem to do anything.

Correct me if I'm wrong!