With the rising cost of brass backflow preventers, is anyone looking at using antisyphon valves instead? Less expense. No valve boxes to dig. No critter-chewed wires. Easy winterizing. Customers asking "What the &%@#*$!!" are these?!" probably remain the biggest hurdle. The only real downside to AS valves I've seen are visual, if foundation soil settling twists an installation, and the inevitable need to replace the vacuum-breaker poppet washer somewhere down the line. Also, depending on brand (like Irritrol) the solenoids' ability to endure weathering might be questioned.