I use it! Just don't believe the hype that it is safe to use with live rock, also becareful with the type of fish you are using it on!!!
I was told by the manufacturer's agent not to use it with Angel Fish, puffers, eels, and I forgot what other fish she said; it's been a few years since I used it.
Definitely use it in a hospital tank, and use a test kit to insure proper dosing.
I used it this week and I'm still watching to see how it works. I bought the mardel antibiotics too to quell any secondary infections. My akindynos clowns had a bad outbreak last week.