I look at it this way........I keep mag chloride, mag sulfate, and calcium chloride on hand. I test regularly, so if I ever have to do a gross magnesium or calcium correction I just do it.
There are others on this board with large systems that use IO, don't be fooled.
Jenn had a great deal on the barrels of Salinity. I like that brand as well because of the guaranteed analysis. Bought one of those because it was a great bargain.
But IMO, for my own purposes, I think of most commercial reef salt as a bulk commodity. Manufacturers can try to differentiate the brands as much as they want thru marketing, but as long as I can correct for calcium and magnesium levels as needed, I don't think it makes a huge difference which brand I use. I have used Salinity, Reef Salt, Instant Ocean, Reef Crystals, D&D, and besides some differences in the amounts needed to get to a SG of 1.025, I have not seen any major impact on my corals by using any over the others. I use a calcium reactor, and if needed, which it rarely is, I can adjust mag and calcium levels whenever I need to.
So I tend to go for the best price on major commercial reef salt brands when it is available, because I don't see much, if any, differences between the major brands. That is just my experience.
