Ask HN: Your thoughts on Lisp, and how stable is Arc?

I was inspired by some of Paul Graham's essays to start exploring Lisp, and I'm so glad I have. Even after just walking through one tutorial, it seems clear to me that Lisp (and functional programming in general?) has big advantages over Python, Perl, C++ and Java - the languages I've been using. The most surprising thing so far: after getting used to the idea of S-expressions, I feel more at home with Lisp than with traditional-syntax languages.

I want to start using Lisp in my own projects whenever I can. I've started with Common Lisp because it seems like the incumbent dialect for all-purpose programming. Though really attracted to Arc, I've gathered it's still relatively unstable, is this accurate? (If yes, I may still get involved with the community development.) Any other comments for a new Lisp programmer or about Lisp in general?