That's a great change. Containers are one of the things that made me move back from Chrome, it just feels far more useful to me to mix different contexts in one window than having to run entirely separate browser profiles as I had in Chrome. The one thing that prevented me from creating more elaborate container setups was the lack of sync, it just gets too annoying to set that kind of stuff up repeatedly. But with sync I'll probably look at creating more fine-grained containers than the basic work/personal setup I have right now, e.g. separating out Google in a separate container.