I replaced a very noisy Jabsco pump with this one and so far am very happy. It is much quieter than the Jabsco ParMax Pro and provides a smoother water flow without cavitation. The original variable rate ParMax was a great pump, but apparently they don't make them anymore and everyone has gone to single or two speed pumps. They have a tendency to not provide consistent, smooth water flow. Shurflo uses a pump assembly that regulates the pressure inside of the pump by recirculating it. It is the best alternative to the old variable rate pumps that I've come across. We liveaboard and use our water system constantly, so I'll be looking to see how well this pump holds up over time.