10.4 Server Spam Filter

I'm (finally, a little late but oh well) Upgrading my server to 10.4 Server. The main reason is because I need spam protection and 10.4 comes with Spamassassin. How does it work? How effect is it? How easy is it to manage? Does it update itself without hassles? Are there any bugs or anything I should know about? I tried manually installing spamassassin on my 10.3 server, but it was way too much of a pain in the ass, plus there are some other reasons why I figure just upgrading to 10.4 will make things easier, in general.