It's working great as are the other filters that we change more frequently. We got the unit about 2 years ago and just replaced the 2-year filter. Other than the high price for these filters they are a valuable piece of equipment to have. Have you done calculations to show if it's economical (with the cost of the unit of over $600.00 and recurring costs for filters as compared to 5-gallon jugs that are delivered and replaced by some of the prominent vendors? With almost everything going up in price, it's going to be challenging for retirees to keep paying higher and higher prices for filters, assuming the until keeps working. What's the average life of your Water Drop RO 400 GPO system?