It's always nice to hear that people are deriving utility (other than just the fun of discussion) out of all the stuff we talk about on this site. With that said, I wouldn't emphasize the first benefit you listed too strongly.

Yeah, it's true that surrounding yourself with people who agree with you on stuff is fun - and productive, if you agree correctly. But it's not a specific benefit of rationality - if you happened to believe that decisions should be made by searching your heart for the Holy Spirit's guidance, you would get exactly the same sense of subjective well-being by joining a group that believes the same thing. So to someone who isn't already a member of your rationalist in-group, this isn't going to look particularly appealing.

On the other hand, the second item does seem like something that's specific to a rationalist community. I would be curious to see if anyone could think of more things like that - if enough come up, it could make good reading for people who aren't necessarily enthusiastic about the topics LW covers.