I would imagine it is a glorified oil change. I have 16,000 miles on mine and was looking at adjusting the valves until I came across this post. I strongly recommend reading it. Sorry, you will have to do a copy and paste to your address bar. I don't know how to put it in as a link to click on.
http://rswarrior.com/forums/p/24142/284034.aspx#284034
I believe a 16,000 mile service is basically a valve adjust and oil change. Maybe a few other things. Not worth it in my opinion. Change the oil yourself, and with the money you saved, buy some mods!!! 