IMO Lightning based items are generally favored in comparison to other elementals. Arguments:
1) There is none of elemental items/weapons which would have comparable affix like SoH TF or Odyn, moreover special affixes are on the 2nd affix set which is rather less significant that primary ones. Not saying that for example other elemental based weapons legs are simply slower(Devastator, Uthar Roar, Burning axe of Sankis) than lightning(SoH etc).
2) There should not be class sets which favor one elemental damage over other for exampleRaiment of a Thousand, This is unfair for uther elem builds. What do you think about it ?
Electricity is much cooler than cold, poison or fire.
Fire has Cindercoat and many other fire boosting stuff for other slots while Lightning is mainly just weapons. Wiz Firebird build favors fire pretty much and Monks do also have other sets than Raiments of Thousand Storms.