I don't know about them, but I've found the community around it both intelligent and accepting. That's not what I've come to expect from the word rationalist.
I remember at the peak of the 2016 post-election meltdown the SSC subreddit hosted a sort of "ask Trump supporters anything" thread. Despite the absolute insanity of the time and only a minuscule fraction of the sub's readership supporting Trump, the conversation was interesting, calm and uniformly civil.
There were a few Social Justice types that used to comment there too; again, all very civil, although there was sometimes the sense that they were regarded as an interesting zoo exhibit.
