Product review (3 stars): It's okay, but not great.
My whole bedroom smelt like a dirty sponge after using this filter for about two weeks. I soaked it in the sink with some vinegar and a very, very small amount of bleach and the smell went away. I also rinsed it multiple times. The filter itself was mostly clean. Hopefully this fixes the problem.

Otherwise, no complaints; however, this is NOT the manufacturer's filter, as other reviewers have stated. The one on the manufacturer's website cost $19.99 (marked down from $29.99) and you can buy a pack of six for $107 and change. That's a bit too much for me, so I'm hoping this vinegar/bleach soak works.