Well as pretty much the "other side" of the zeo debate, my position is that it clearly "works". However it is also more than obvious how it does work (either by design, or otherwise); essentially by inducing corals to bleach, and then trying to control the extent and effects of the bleaching with chemical foods / nitrogen sources. A casual reading of zeovit.com will show that.
Now the interesting part, and the part which is up for debate, is how exactly it does this. I have my theories. Others think i'm crazy, and part of some anti-zeovit propaganda group
If you're up for that challenge and are happy with the risks that come with it, then go for it. But personally it's not my cup of tea.
Layton