There are definitely pros and cons of every salt.
Crystal Sea is cheap, but terrible for reef tanks. All of the levels are low.
Instant Ocean is good, but still not good as far as levels.
Oceanic has excellent calcium and magnesium levels, but the alkalinity is terrible.
Corallife is okay, but has high Lithium levels (which are bad for starfish).
Sera salt is decent with all of their levels except for calcium. It gives you 280.
Kent has very good levels as far as calcium, but the silicates are a little high.
Tropic Marin is the best, but is also the most expensive at $50.
Personally, I use Oceanic because it gives me the best levels and the poor alk is easily corrected by using dkH buffer.