I've never seen a Weathermatic controller installed in 20 years of servicing sprinkler systems so I wont comment on that.
Rainbird has some excellent controllers. I also have never seen a modular Rainbird installed.
I have however seen many many Rain Dials. I've personally uninstalled numerous Rain Dials the past couple years. Probably 20. I used to love this controller. The cabinet is super sturdy. The faceplate is super sturdy. But, the controller has a variety of issues. I don't install this controller anymore.
I uninstalled two Rain Dials I installed in Feb of 2011 just last week. Both have the same flaw on the circuit board. Yep they're under warranty and I'll be sending them in to be repaired. I replaced them with the new Hunter Pro-C modulars. That's what I'm recommending for you.
If you go with the Hunter Pro-C. Go with the modular and not the PCC. I returned 4 PCC's recently. All had issues with the door.
They were however outdoor controllers. I don't recall having a problem with the door on the indoor model. This might be a new issue with the recently redesigned Pro-C's though.
If that was confusing. Here's what I'm recommending.
Pro-C