My idea to make Set gear more interesting and worth it.
Premise:
Set gear and Unique gear is balanced on implicits and affixes.
In theory set bonuses are balanced with Legendary Potential. In reality I think LP vastly outshines set bonuses.
Idea:
Let set bonuses unlock nodes in skill specialization trees.
This opens up interesting build crafting where you can use a set of gear to save less skill points otherwise used on less valuable skill specialization nodes to get to an important node vital for our build.
What specialization a set / set item unlocks could potentially be random to allow wider variety. Maybe use the same drop table that determines the amount of LP on Uniques to determine what skill is unlocked.
In raw power, this change is equal to a +1 to skill Affix, but in reality it is much more powerful and interesting.