yes, there is a difference between the regular salt and the reef salt. everyone is going to have different opinions about what salt is best. the truth is, no canned salt mix is consistent, so they are what they state on the side of the can, before they are put in the can, but they may or may not be the same by the time you get it.
i use a different salt mix each time. i like reef crystals, oceanic, tropic marin pro reef, seachem reef salt, red sea coral pro, D&D H2 ocean, gettanked aquariums "salt water correct" mix, and a few others.
the salt water correct mix from gettanked aquariums is a bit different than the others because you add the calcium about an hour or so before you do your water change, and this ensures the calcium and alk
levels are spot on.
there is another salt mix like that, but i can't remember the name right now.
maybe someone can chime in.
you can keep a tank full of corals healthy and happy with nothing more than regular water changes.