[Luc_H]

According to America's Test Kitchen (on PBS) and the book: What Einstein Told His Cook by Robert L Wolke, there is no difference in taste when a specific weight of salt is diluted in water in blind taste test. All salts are 99%+ Sodium Chloride (NaCl) on a dry basis.

That said, using salt topically is different. Salt is a crystal and the shape affects it's dissolving speed. Regular salt (from mines), is cubic and packs tightly together so 1 tsp of this salt weighs more then... say.. kosher salt.
Cubic salt dissolves quickly on the tongue so the taste is intense (almost metallic) yet kosher salt dissolve slower because the crystal is jagged.

Fleur de sel (means salt bloom in French) is the first salt crystals that appear above the water when it evaporates. The shape of the crystals are different (very feathery) then the regular sea salt and it's meltability is interesting but in equal amounts in water it will taste identical. Because of its shape, it weighs little for its volume.

Iodine is added to mined salt because it lacks in this essential micro-nutrient to prevent a debilitating thyroid disease. (Edit note this statement is not true see later post. Luc H) *Iodine is found naturally in similar amounts (if not more) in sea salt.*

Depending on the usage, I use regular salt in liquids (soup sauces) and kosher salt for rubs and the like. I don't use sea salt because most are ridiculously overpriced but if i get it free.... I'll use it.

Luc