I use it and like it. I think it's one of the better salts, mostly overlooked in the mass market as they only sell to independents, not chains or large MO companies.
Great topic I have done a lot of research on!
BRANDS RESEARCHED:
Tropic Marin
Instant Ocean
Hawaiian Marinemix
Marine Environment
Kent Marine
Some of these look very good on paper but really suck in use. I have found Kent to be my salt of choice. I usually do not like Kent products but this salt seems to be great. I hear Instant Ocean is basically identical with less trace elements. Marine Environment scores high (they include trace element in a seperate bottle) but it does not mix quickly. I used to use Hawaiian Marinemix exclusively but have read some reports that is has 13 times more lead than seawater!!! Fish with ADD
So my advice is to stick with the most salt for your money: