I would say its superior. You can create and add tabs to groups. expand and collapse them. make rules for certain sites to auto open in a group you made. sort based on url or name or last used. rename them. move the groups around visually. I do use it with the vertical tab view and tend to ignore the top bar though so it may depend on your usage.
powertabs will give you vertical, grouping, search, sorting, and some rules behaviour
Does it mimic the functionality of chrome group tabs perfectly?
I would say its superior. You can create and add tabs to groups. expand and collapse them. make rules for certain sites to auto open in a group you made. sort based on url or name or last used. rename them. move the groups around visually. I do use it with the vertical tab view and tend to ignore the top bar though so it may depend on your usage.
It seems a bit too much like glorified bookmarks to me. I’m glad you find it useful though :)