I just so happen to be installing a RainMaster Oasis, with 15 controllers and a Weather Center II, and will be completing installation of the controls this week. All seems to be going well with installation and configuration.
Let me know if you need any additional information. I can update you when system is up and running.
Are you looking to get into designing irrigation systems? If so, I would recommend taking a class that is taught by the Irrigation Association, or a local community college.