I've had really good results.
My dosing was kept at about 15-20 ppm. I did find out you really need to stay on top of your pH testing and buffer addition so you don't drop the pH too much.
My zoas all opened eventually, except for one colony which I believe got eaten by someone.
My skimmate got NASTY as heck - warning!
There's no algae and no cyano anywhere at all, and the chaeto and caulerpa in the fuge are doing great. I've never had such a clean tank.
I slacked off the dosing for a couple of weeks, but began back again last week. I found the exact same buffered Vitamin C powder as Pufferpunk buys online at Healthfoods Unlimited in Miamisburg.