PvE experience pretty much.
With Momentum you give yourself a 4s window in which you have to put things into following a priority list:
So for every Momentum you have to go by ear and judge yourself.
The absolute ideal burst rotation is Fel Rush > Fury > Fel Barrage. In the next patch with First Blood, you could go for Blade Dance aswell straight after Fel barrage.
Speaking of next patch, I can see some serious damage nerfs incoming. Our deeps is pretty bonkers already, contrary to what I foresaw. The class scales like there's no tomorrow and our template at the moment is really really strong.
Will have to see after the stats are nerfed and stuff.