Rated 3 out of 5 stars

Good addon, Very innovative idea, Helps a lot.
But one problem is it dosen't match with persona. On some ( Royale Zune Aero in my case ) the tabs gets blurry, the tab lebel becomes hard to read etc. etc. Good thing Firefox restart isn't needed to go to the default theme from a persona, still its kinda boring, you know. No disrespect, Cluster Tabs had made my life a lot easier, but I wish it got these problems fixed.