I have never used it, but it sounds really interesting... I wonder what the mechanism of action is in the zeolite that does all of that stuff (inhibits growth/production, neutralizes ammonia). The best thing about it, that I see, is it inhibits transmission of toxoplasmosis... pregnant women rejoice (I still wouldn't take less precautions though). Is it expensive? If I could find it around here for a reasonable price I would try it this week and let you know (my cat's are not picky about litter so I wouldn't necessarily need a transition phase).
My only bothers are it doesn't come from a renewable resource (same as clay litter) but depending on how much you go through on a weekly basis this may not be a deal breaker. Also, what if it's ingested? They talk about less disease transmission but what if my dog helped himself to a kitty box buffet (hasn't happened in years but that doesn't make it impossible).
I currently use Nature's Miracle but I am "testing" World's Best Cat Litter in my most trafficked cat box since it became available at Petsmart here. So far I think I like the World's Best Cat Litter more because it clumps better and the clumps seem to stay together better (I clean my litter boxes constantly). I also like that it is not scented and comes in a much larger bag. I don't seem to be going through as fast. It doesn't seem to stick in my cats fur as much but somehow they seem to track it WAY more. Its also more dusty than Nature's Miracle but I would give those things up for better clumping since I have 3 cats and 4 litter boxes.