I don't know the first thing about this controller. I do know however that Irritrol is a trustworthy brand.
I know a lot about computers and a lot about sprinkler systems. The last thing I want to do is install something like this for one of my customers. If they get a virus on their computer they'll be calling me wanting me to repair the sprinkler system.
Sounds like one huge headache to me. If you install it yourself I'm all for it.
www.sprinklerwarehouse.com/Irritrol-PC12-INT-PC-Control-System-p/pc12-int.htm