dmorison - 4:42 pm on Jul 16, 2013 (gmt 0)
I do exactly the same with some of my web properties where "www" doesn't fit and "example.com" is the brand, and the DNS setup is exactly as you describe - an A record for "example.com" to the server IP address, with "www.example.com" set up as a CNAME pointing to "example.com". The Apache configuration on the server then redirects any request to www. to the equivalent non-www URL.
You should really use example.com in your posts to WebmasterWorld, but in terms of your question regarding SEO and whether or not it makes a difference, I don't think so as long as you make sure that www. is redirected to the non-www preferred version under all circumstances, and I think it's OK to cite a household domain name in this case - if you go www.slashdot.org you are unceremoniously redirected to slashdot.org ...