in general, the elemental is for medicine and the salt is food. once all the Iodine deficiency problems have been reversed and especially once sufficiency has been achieved, Iodide is all ya really need. i take the SSKI 2% with magnets just for the kick and because i can. the plain SSKI will do the trick for daily diet supplement.
and finally, dont forget that KI is only 3 quarters iodine. so a gram of KI is like 750mg of lugols.