I don't deal with 5004's much at all. Mostly see PGP's. For some reason Hunter is the most used in my part of the world. Anyway, strictly speaking about wiper seal life/failure what do you see in 5004's versus PGP's? Plastic not metal. Just the wiper seals. Nothing about distance, spray angles, lobster dinners, hats or dinner cruises from the manufacturer. I just replaced 10 PGP's at one residential place due to wiper seal leakage. Date codes from 1999 and 2000. Pressure was poor due to all the combined leakage on 3 zones. This was in very sandy/gritty soil. Shafts all scratched up, scored. Two-thirds of the heads were also too low in the turf. Some near the driveway got run over and pushed down. Others I'm thinking the turf roots "grew" higher over time.