Comment by ThatPlayer

Me and my team are planning to move to mattermost, but their Slack import just isn't 100% yet, so we've been holding off on it. For example right now it doesn't import the chat logs of any bot account.

https://mattermost.atlassian.net/browse/PLT-48

While we're not in the biggest rush to move to Mattermost, it does seem to offer more than Slack right now.