It's actually not mine. I'm setting it up for a school lab, and they just need really basic AFP sharing and DHCP routing. They bought it over a year ago, and no one knew how to set it up, so it's been sitting new in it's box since then (don't ask me why they bought it). I tried to setup OS X Server, and it just seemed really complicated. What I could have done in OS X client in a matter of minutes is taking much longer in the server version. I don't need to setup Open Directory and all that other stuff, I basically want to share some shares and have the machine act as a router.
Since I posted this though, I've discovered that OS X client only allows up to 10 users access at a time through AFP, which will not do. So, it's a moot point, as I need more than 10 users. So I guess I'll trod along in OS X Server. I'm still curious though if the Xserve is limited to just OS X Server.