I was introduced to the brand by a friend of mine, who happens to own an LFS, so probably does have to treat fish more often than us hobbyists. He originally recommended eSHa 2000, which has always worked reliably and very well for me, but he did, at the time, mention that he found exit (anti-whitespot) to be less effective than other brands. He did go back on that last year, saying that there is no difference between various medications, but as I have only ever treated for whitespot once with a different medication, I am yet to find out if what he said about exit is true.Esha does not appear to have a lot of marketing clout or shelf presence here, but i certainly have faith in the brand now.