Kookie track cogs - anyone used??

Has anyone had a chance to use the kookie cogs?

http://www.kookiebikes.com/store/product.php?productid=45&cat=0&page=1

Im interested in trying a teflon cog on the track bike, but im worried about how long the coating will last. Any opinions??

Thanks

i have one of the non-teflon ones. very happy.

I ended up getting one for the track bike. Looks bloody nice in real lifeā€¦