SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I'm new to this whole irrigation thing, but I'm in the process of putting in a system at my house. I live in N. Iowa where it obviously freezes in the winter. In addition it will often freeze and thaw several times in spring and fall as the seasons transition from one to another.
Does anyone from a cold weather environment have any experience with these FR PVBs, do they work as advertised, and are they worth the extra $$ to put in a system?
I realize I would still have to winterize this, so I'm trying to figure out what the benefit would be of the freeze resistant types.
Thanks for your help,
Swen