Lucky charm isn't to strong, because it gives so much extra loot, it's to strong because it gives loot on your level, and not from the area level. From halfway act2 till the end, (Driftwood part) I was 1 to 2 levels above the enemies in every zone, as I did all the available quests possible in that act.
The loot I got from lucky charm was because of this, always better then the loot from drops. Even random epic/legendaries where better then most divine/unique items dropped, because of the insane stat scaling in the later levels.
They should have just fixed that; Lucky charm (and maybe even vendor) items aren't based on your level but on the zone level. Makes drops matter again, if you are overleveled (which is very easy if you explore everything and do almost every quest).
