It doesn't come with
any documentation, but there is a support page online with instructions on setting up with airport. It also tells you what to do if you're on O2/Be LLU - that requires configuration (which you can do by plugging into your mac's ethernet port) but if it's just standard ADSL then you're good to go out of the box.
The only downsides: I needed to upgrade the firmware to get a solid stable connection, not too much of a problem, except I had to do it with Firefox rather than Safari (scary moment when I thought it had crashed during flashing) and I had to go onto the Draytek forums to find the firmware.
http://www.i-lan.com.au/downloads/firmware/Vigor120/Beta/0813/V1200813332201.zip
Is the link, to save you time. I would try it without upgrading first, as it is beta and after flashing, the DSL/Internet lights don't work.
The REALLY annoying thing is that there's no way (that I have found) to view the ADSL status page (or telnet) to see sync rate or change configuration.
The really GOOD thing is that you can finally use back-to-my-mac and you no longer have two routers between you and the internet.