Works well for our cat. The water here is pretty good quality so we do not use the filter. At first he was hesitant to use the fountain, but after a day was used to it. I think he drank more often than from just a dish. I found that it wasn't too hard to clean, but maybe our cat didn't make too much of a mess in the fountain. You do have to add water at least every 2-3 days to keep it full. Generally quiet, but if the capacity drops by more than about 15 oz or so it becomes quite noisy. I haven't yet tried the larger capacity add-on yet, though. I also keep the regulator half-way to reduce any noise. Price at Amazon is about $10 cheaper than the retail store.