When comparing TabCenter vs Tree Style Tab, the Slant community recommends Tree Style Tab for most people. In the question“What are the best tab management plugins for Firefox?” Tree Style Tab is ranked 2nd while TabCenter is ranked 3rd. The most important reason people chose Tree Style Tab is:
Tree Style allows you to have at least 10 tabs open.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Frees up screen real estate where it's critical
The tab center is about the same size as the regular tab bar, but vertical. Most people have a wide screen monitor, and therefor plenty of horizontal space to spare. Vertical space comes at more of a premium. Tab Center addresses this really well.
Pro Organizes multiple tabs
Tree Style allows you to have at least 10 tabs open.
Pro Visibility
It lets you see everything you want to see and auto-hides those you don't.
Pro Fairly stable
It does not seem slow, you'd never have problems that will make you disable the program.
Pro High customization
Pro Theme support
Cons
Con Dead
Con No per-group customization
No way to colorize or otherwise highlight a group of tabs. Can reorder, but not the same.