I just installed one of these and it is pretty straight forward with the guide that is attached to this thread. I did have to upgrade the unit to get it to work and on Ver.1 you have to use either an HTTP server or SD micro card only. After the upgrade you can do future upgrades with a usb thumbdrive.
After configuring per the document I noticed that when a DB test is ran on the save, it reports the max call setting of 4 on the SIP phone group as invalid. The version of the system is 6.0 SP1. Not sure why it reports as invalid.