All rain sensors are simply switches that become open-circuit when they become wet. Therefore all rain sensors are compatible with each other.

I had a Rainbird RSD-Bex installed with my new system this summer and I am very disappointed with it.

We had some pretty torrential rainfalls this summer, which should have provided enough water to last at least a week. The Rainbird sensor turned the system back on after only 24-36 hours. This was despite the fact that I had the drying vents closed as much as possible.

I also noticed that it takes at least an hour of moderate rainfall to activate the sensor.

I have been considering the purchase of the Hunter Rain-Click, primarily because of it's (claimed) instant response to rainfall. I would like to hear if anyone has had good results with this model.

The Hunter Mini-click, which you mention, does not appear to have the instant reaction to rainfall.

I am going to go ahead and try the Hunter Miniclick. I will post the results as soon as I have any.