This is very simple to set up and it's indeed lightweight. Pretty good yslow scores, etc. ... And I like the overall aesthetics.
Now, for the final thing -- this could be a 6 star plugin if we could find a way to include Facebook / Twitter login / registration capabilities.
I recommend this over BBpress or whatever it's called and WPBB, which has Facebook integration but nobody can get it to work and the support author doesn't reply to anything anymore.
Great work authors, and if you ever have plans to integrate Facebook/Twitter login & registration, I'd love to know about it!