I’ve been keeping an eye on Discourse since it was announced and I’ve always liked it. It was even in my shortlist for the last forum I launched. Unfortunately I think at the time it just didn’t have the features that my users wanted (who, in fairness to Discourse were coming from and used to a vB forum).
Recently we needed a forum to discuss Opal & Volt related strategies, so I’ve just last night put up a forum at http://metaruby.com (A general Ruby forum with private sections for our strategies teams.)
It’ll be interesting to see what kind of feedback we get (and whether it takes off as a general Ruby forum) but in the meantime I thought I would post some quick feedback.
Well I’m very impressed! Especially with the speed given I was actually quite concerned that using Docker would be unnecessary and result in being inefficient, or worse, a resource hog. But my concerns seem unfounded, in fact top stats show that Discourse is using less resources per page view than my Xenforo, vBulletin and even Wordpress sites! And some people still think Ruby is slow!! Kudos to @Sam and everyone else on the team who’s managed to squeeze so much performance out of it.
I’m also surprised how easy it is to actually set up. No more manually creating a database, uploading files, having to sort out the backups, worrying about versions of PHP, security (apart from what’s probably already on your server) etc. It’s actually become so easy that I’m wondering where to put my next Discourse instance! Haha.
I can also now see where the DC Team have been focusing their efforts - features and stability. When I first put up a test install (for the site in the link above) the Admin CP was pretty bare - it isn’t anymore!!! So many features and settings!
Anyway, credit where credit is due - the team have done a great job 
I do feel a little bad that we haven’t created a custom theme as we’re quite known for making pretty good forum skins. But the default skin in DC is actually pretty good - I’m certainly happier with launching a forum with it than any other forum with their default skin. However if MetaRuby takes off, and/or there is a lot of interest in people wanting to see us do a custom skin we may get to it sooner - but we’re just really really busy atm with so many other projects. (So I hope nobody at DC takes it personally!)
Anyway, I have a habit of rabbiting on - well done and thank you to all the Discourse team 
(If anyone’s interested in joining a Ruby forum, please do consider joining us!)