Since I wrote the article I now own three sets - one standard Jarts, one adjustable Javelin Jarts, one Slider Jarts.
I throw them often. The Sliders are my favorite, they seem to have a more fluid line of flight.
One set I found at a yard sale. The other two I bought at ioffer.com, though it appears that they stopped listing them there, too.
A good set sells for about $100, the sliders can fetch nearly twice that much.