One of the biggest differences I saw wasn't so much on regular dosing, although PH seems much higher and more stable, but I don't have to dose like crazy on my newly mixed water to get the parameters to target levels.
Most other "Reef" salts I'd tried still took a lot of testing and adjustment before even using the water. They all either had high CA and low PH/Alk, or fair Alk levels and low CA. Very few had decent Magnesium levels.
Salinity on the other hand is pretty dead on for what I'm targeting parameter wise, with out much tinkering on my end, and also much more balanced.
The hard dirty crust is strange, I've only ever had a slight white dustiness on the first couple batches I mixed when using warm water. After switching to cold water for mixing, it's always nice and clear with no residue at all.
I'm two buckets in now on Salinity, and the corals have never looked better.