To oggy:
I am talking only about EF build. It is also good to understand, that your benefit from haste is not only the 13th tick of EF. We can say for sure, that going pure mastery with EF is a bad way (I saw numbers, it sucks, if its right). Going only haste means, you need more regen so you cant go OOM during fight (I cant afford this right now, with my low gear - maybe with HC pieces). So I assumed, that the best way in my gearing strategy will be (and i guess with 553 items it will be still the same) a combination of mastery and haste.
And now, if I want to have haste on my gear, it would have some personal cap (due regen limits for example.), and this is the value, where i get the 13th tick of EF. So my mana regen can stay on the same level and i dont loose too much of my mastery for progress.
Please tell me, that I am not stupid, because I am confused too
and very very much