I have. Good luck getting it running on a host unless you're reasonable proficient - you're not doing it on anything less than a VPS, but the bottom most plan ($5/month) on Digital Ocean will be enough for a starting forum.
So, fun fact, I used to frequent a forum that was full of *very* technical people. Also, very intolerant of stupid. Very, very intolerant of stupid. And their forum from like 2006 to 2014 was a thing called Community Server. The community at large, being very technical people, had great sport hijacking the forum and doing things with it that it wasn't designed to do. Like adding speech bubbles to the poster above you's avatar, through careful code in your signature.
And in 2014, the site owner - who happened to be friends with Discourse's founder - agreed to migrate to Discourse.
Oh dear.
This was, as I say, 2014, so this was early Discourse and I daresay that group of people were the best round of QA Discourse had because this was a group of people who build software, who *do* software and who aren't afraid to say *exactly* what they think. So all the technical issues we found - and we found some utter howlers, up to and including breaking the entire forum for hours at a time just by trying to log in in a very specific way - they all got fixed.
The straw for the camel, though, was Jeff Atwood, its founder. You see, this was early days and Jeff still really really stood by the mission of Discourse's underlying company, "Civilized Discourse Construction Kit". In his mind, the reason forums were so awful is not just because the "90s toxic hellstew forum software" was bad and needed a rethink, the culture needed shifting too. And we learned about this the hard way - take a well established community, change software (with agreement from the community), but then let that software's team come in as moderators and... *aggressively* moderate.
Jeff has a few beliefs. Topics should be short and stay on topic. Even though that's not what people do, they go off topic and meander and prevaricate. At one point it was likened to being at a party and told, 'Oh you want to discuss *that*? Please go in the next room.'
And Jeff *did* proactively police this, locking topics and splitting topics that he thought were too long/inappropriate/off-topic etc. etc. as this is "uncivilised behaviour". I believe the letter to the admin asking him to remove Jeff was for many years the single most liked post on the site.
And if you're feeling brave, this is the post uncensored and full of expletives and anger:
https://what.thedailywtf.com/topic/11531/i-m-a-grumpy-cat-an-open-letter-to-alex for context: Alex is the admin, Lorne was a contributor to the site and the forum. It is from Discourse's early days, and early in its adoption. The site moved off Discourse approximately 2 years later. But only after so much anger and hate. I had so many arguments with Jeff myself as well, seeing how I'd spent a large chunk of 2009-2014 myself on forum software which I thought entitled me to voice my own thoughts, especially when he was openly and actively dismissing what I had helped work on as 'toxic hellstew'.
I don't know if Discourse is *better* now. A breeze through meta.discourse.org doesn't fill me with great belief that it is wildly different but the most striking feeling I get is that Jeff finally listened to what he was being told and dialled it back a bit on the rhetoric because some of the things we told him in 2014 have been adopted in part in the years since. But I'm not sure I'd call that 'better'. It's different, and it has a few interesting ideas implemented... less than optimally... but honestly... I see Discourse in a few places and I don't tend to stay long.
The guy spend 2 hours typing his rage. 
