I have used this with my OPII for almost 2 years now, works great although I did have it lock up once in that time not responding to commands requiring a power cycle. Just looks like 8 units to the OPII. I also have a rain sensor hardwired to a zone on the Omni to prevent the sprinkler program from running and display a message.
I love being able to manually turn on zones from my iPhone out in the yard when I'm testing and working on the sprinklers. I have even thought about having my x10 motion floodlights turn the sprinklers on for that area if tripped while the system is armed for fun

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Has anyone attempted to integrate this with a HAI controller? This would be a great solution to my location issues.
Maybe there could be a My:Ro UI for this too since there is no integrated HAI irrigation UI.