As you can see from the article, this is not truly a comparison between Karma and Mocha, but I wanted the title to be intentionally provocative, to sparkle some discussion around the topic :)

We use test-automation for real browser testing but prefer to rely on quick and functional unit-testing, thus the choice to go with jsdom.

Regarding the community, you're right, there's a `karma-something` for every need. However, mocha is pretty popular too, and getting momentum by the day. Also the fact that it simply runs on Node makes it quite easy to obtain what you want without extra plugins (e.g. coverage).