I love the concept of keeping several contexts. Now I can keep the must-login-but-will-track-your-online-activity sites in their own containers, and surf the web without Google/Facebook/... following me on every click. Also makes me feel a bit safer, knowing my work and bank related website cookies cannot be abused by random sites I pass by. A missing feature however (and the only reason I'm not giving 5 stars) is that it isn't linked with bookmarks, it would be so much better if bookmarks could have a setting "open in container", that would probably also fix Tab Stash, were now all tabs are restored in default container.