Ranked in these QuestionsQuestion Ranking
It lets you see everything you want to see and auto-hides those you don't.
Pro Organizes multiple tabs
Tree Style allows you to have at least 10 tabs open.
Pro Fairly stable
It does not seem slow, you'd never have problems that will make you disable the program.
Con No per-group customization
No way to colorize or otherwise highlight a group of tabs. Can reorder, but not the same.