We survived over the past five years without it, so I wouldn't say this is a product that every cat needs. However, once you've used it, it's difficult to switch. I can only speculate, but my cat appears to appreciate it very much. Just be sure to wash or wipe the water pump as well. I really hope the filters are more affordably priced because they look to be nothing more than active carbon water filters in a fancy case. Recommended all around.