I have not tried them.
Somebody on the Icebike list did try them, and remarked that the Airfree tires are made of some non-rubber elastomer and have zero traction in rain and snow. That is to say: these tires are only for fair weather.
I've gone about 2,000 puncture-free miles on my Schwalbe Marathon Plus this year -- why should I give up the well-documented virtues of pneumatic tires when I already have had a puncture free year?
The idea of a tire that will never flat is appealing, but there are less drastic ways to approach that goal.
Paul