I find with things like this that it's a million times easier to have the feature turned off by default, and then whitelist your own specific use cases.
Thats what Ive done with Javascript on the web. My browsing experience is so much better without downloading 20mb of ad network code on every page load, that I could never go back even with the minor annoyance of having to click "allow javascript on this site" every now and then.
Moves your chat or compose box into a new window. Useful for some people's workflows, less useful for others. I sometimes pop out a Hangouts chat so I can pin it somewhere I can see it while doing something else.
