Well this... was a bit of a thread revival. Now I feel a lot of lurkers will look over it, getting old or confusing information. This post will answer what it does as of now, 5.2, within this expansion.

Determination is the most simple of all the secondary starts. At level 80, every 25 Determination increases the healing you do and the damage you do by 0.1%.

That's all. You're done. Leave this thread and let it go in peace.