Just look at the responses here. Long time reefers, IO, fairly new reefers choose whats popular like red sea and AF, or what the hype machine BRS tells them to use.
Salt will not magically make your reef better. Among the major brands, salt is salt, just choose what matches your price point and parameters you want to keep.
Long time reefer(going on 20+ years). I have used just about every salt on the market, and always find myself going back to plain jane purple box IO. Price is decent, it's one of the most consistent salts on the market, widely available in just about any pet store on the planet, and just about every large aquarium/museum on the planet uses it.
Those are facts that cannot be disputed.