Product review (2 stars): dry air
I love this humidifier, but I finally had to get a new filter.  Since I've put this one in the air in the room stays pretty dry.  I think it's better than not having it on at all, but it's not nearly as humidified as it was when I was using the filter it came with.  I have no idea what the difference could be, but that has been my experience.

And it's not just the feel of it - the thing never switches off like it used to (when it got humid enough).

I have no idea what could cause this.  I'll search for a different brand.