Water Fountain vs. Water Dish for cat?

We use a fountain, with about a half-gallon sized tank in the back. The veterinarian says that it's the best thing for the cats, since it keeps the water filtered. I believe the cats themselves like it better that way, plus the stream of water entertains them sometimes even if they're not thirsty. I find it is way easier to deal with water this way too, since I only have to refill the thing and thoroughly clean it out maybe once every two weeks. It makes an annoying sound if it starts to run low, so it's hard to just forget about it.