The search and hide/unhide function seemed interesting to me, but in my opinion the Tree Style Tab add-on is superior. Perhaps that is because TabCenter is aimed at a less technical audience [1].
Hierarchical tab structures are more valuable in my opinion, because it implicitly groups related tabs together. The structure in which tabs are opened reflects my workflow while opening them and allows me to e.g. close all tabs that were related to a certain problem. It does however lack a search function and some sort of versioning, as I find my tab-bar clutter over time. Perhaps a aging approach could be helpful for me, but I have yet to come across something better than Tree Style Tab.