Only one thing i like more about frost enchant in copmare to lightning - is consistency of procs. With frost one - that "frostynes", or whatever the name is for that perk, prok more often than that lightning strike from perk tree of a lightning enchant. And also dmg from frost is higher on basic attacks, and that prok is just double the dmg. But with lightings it's 3 or 4 times from normal hit's additional dmg.
So honestly - over all dps will be pretty much the same with both EoL and EoF. But frost just more consistant.