Mattermost sports higher performance, uses Postgres, is a pure server side application not using up too much of system resources on the client side, and gives an overall enterprise grade impression in general.

Updates go smooth without a hassle, everything is organised logically, and the integration with the OS is absolutely stable. Apart from that, the underlying runtimes and code are mature, proven and stable.

The developers are maybe a bit more cautious in regard to introducing new features, but they maintain a stable experience, not breaking the codebase in order to hastily implement bells and whistles, which are not yet ready for production. Documentation and debugging are fantastic, so running this in enterprise production environment is absolutely approved of.

We chose RocketChat over other communications suites like Cliq or Slack mainly because we can self-host it on our own infrastructure. Since we have quite some projects going on which demand that we stay in touch with a lot of different stakeholders, pricing was an issue, too. With RocketChat, we have a huge set of features basically for free, RC offers apps for all major devices and systems and overall, we're very happy with it. The only downside is the limited amount of apps and integrations, but we can make due with what we have available.