Now up and running:
We're a makerspace for Londoners South of the River. Been around in some form for a couple of years, but only just opened our long-term home in Herne Hill. Previously used Google Groups and Mediawiki.
Done a little bit of custom styling to make conversations flow. (We've been using Slack too, so people are used to uninterrupted text)
We're using Wikified topics for documentation. The functionality is sparse but good enough. Having the same interface & usernames is worth it.
Next step: A plugin to link up with our hand-rolled membership payment system so that Discourse accounts can be automatically promoted to the "Members" user group. Wish us luck!