My house is currently using the Amway treatment water system. I am not sure whether it is your mentioned e-spring system but it has also a combination of carbon block filter, ultraviolet light with an electronic monitoring system. No offence but their lifespan based on the monitoring system is very short.

There are only 2 peoples including me staying in the house. The water usage is very little but the lifespan of the carbon filter and ultraviolet light is about 6 months. Each time u change it will cost you a bomb especially the ultraviolet light. If I remember correctly, it is about 300++ for the replacement. 

So now I din bother to change it. I still used the filtered water but I will just boil it again.