What are some alternatives?
When comparing Simplified Tab Groups and Simple Tab Groups, you can also consider the following products
Tabs Outliner - Next Generation Session, Windows, Tabs Manager and a TooManyTabs Solution That Really Works.
Conex - TabGroups married with Tab Containers and bookmark & history search
Tab Workspaces - Organize your tabs into workspaces.
Panorama View - Tab Groups with Panorama View. Lets you easily Group and manage Tabs visually, with tab hiding.
Sidewise Tree Style Tabs - A dockable sidebar for Chrome featuring vertical Tree Style Tabs, Tab Hibernation, and much more.
Tree Tabs - For better customizing tabs in Firefox.