I won a free bag of it from Tunze and received it earlier in the week..
Well, its about .50/gallon to mix it but I like it. I mixed up 10 gallons today to test it and so far the alk, calcium, and ph were right on the mark of what I am used to getting with Tropic Marin Pro Reef Salt. It mixes very quickly. I am used to paying around .32/gallon for Tropic Marin but I doubt that I will spring for the Tunze salt (Premium Aquatic sells it).