from all the info have ever seen, both salts list nearly identical mineral profiles. i really believe that its a personal choice with those two. i prefer the celtic Sea Salt between the two, but i prefer himalayan salt over both.
also, there has been some concern over the possiblity of contaminant in the celtic sea salt due to ocean pollution, but i do not have any specific info on that.
with the redmonds or the himalayan you don't have to worry, as they both come from ancient salt deposits formed long before man had a chance to pullute them.