Well. Its not going to be optimal in either way Choose which of them you play 90% of the time. I play Affliction. I hit cap, get haste to 4717 (these numbers have to be exact or higher, else u won't gain the tick) - And mastery from there. Seems to be working great.
In terms of the rest of the thread, I was hoping to see some destruction fights aswell. For some reason, Demo haven't really bought me. I rather want fancy burst, than AoE madness/Movement madness. But we´ll see, going to try out different stuff.