Product review (4 stars): Good for their purpose.  Rechargeable/descaleable with a vinegar soak.
Work as well or slightly better than the more expensive Kaz ones.  Not as good as the original ones with the thick blue felt layer on the outside, but I found I can completely renew these by submerging them in a tub filled with white vinegar and hot water for about an hour.  We have fairly hard water and these will scale up within 2 to 3 weeks of daily use.  I used quite a bit of vinegar, maybe a half to 3/4 gallon with enough hot water to submerge 2 of these filters in a standard 18-gallon storage tub.

It's hard to say how quickly they wick water into the air, I feel they're not as fast as the blue felt ones, but it's been super cold and dry lately, and we're trying to humidify big spaces.  These bring the humidity from 15-20% to 40-50% in a few hours, but also cool the room they're in a few degrees.