Product review (5 stars): Seems more efficient
The new "uses less water" panels do seem to hold up to the claim.  I'm using one in my Aprilaire 550 whole-house humidifier.

While the standard Aprilaire panels are made of aluminum with some sort of coating, these are made of fabric so the water is absorbed into it instead of just running down the surface.  They are made from the same sort of material as water-wick pads for table top humidifiers. The principle of using less water is that the air flowing through will pick up moisture faster so the whole-house humidifier will not be "on" as often.

The only downside to the fabric material is that it will build up with the minerals from the water and eventually no longer be absorbent.  So while I might be able to get away with using the Aprilaire panels for 2-3 years, this definitely has to be replaced annually.