is the one from mixnball, you get a toxin free organic coating and they give warranty of 5 years on the coating which is more than enough. i heard people say the herbs keep their smell and taste... who knows? you can only know after you try it.

i would post a link but thats not allowed here, anyway they do give out a free grinder every month so it worth the search.
look for mixnball, it should come up
toke it easy