Since non set armor becomes near USELESS later in the game. How about a armor skill line, like heavy light med, that makes it not so useless. Like giving % bonuses to your stats. Giving you high return from enchants, or even a final passive like, for each non set piece you have on, you get 5 pts to health magica and stamina. Would help balance out the difference and have the armor be used.
OR make all light heavy med, passives, do 3x-4x there base effect for the pieces of armor that don't have a set bonus. So you actually have to give up something to have a cool set effect / bonus.
Circuitous brought this up in a pts thread and I felt the need to post it here and see what the response would be like. I think this is perfect.