I've never used it. I do use Nelsonite and have for many years. Nelsonite does have some drawbacks such as odor and harmful chemicals. This stuff supposedly lessons these drawbacks. If this is true and the stuff works as good as Nelsonite and the price is not to much higher then it would be worth looking into.
I've been using it on limited basis, trying to get away from Nelsonite, so far so good. -* Keep in mind that it takes a while before you can really tell what works and what does'nt