Redirect to either the wwww.domain.com or just domain.com, so you won't have duplicate content as seen by Google et al.
But apart from that, the only reason to go with a
www.domain.com is that if you have a CDN or image server you'll want to serve from a subdomain like images.domain.com
In that case, you'll get better performance from not passing cookies to your static content only subdomain with every request. Serving from a URL without www, will pass cookies as that's the root domain. Serving from a URL with a www won't pass cookies because www is a subdomain and cookies don't pass across the subdomain barrier.
Otherwise, do what you want
Life is short.