Originally Posted by
Gnomognomo
Affliction is definitely viable in NH. Said that, logs shows that demo has better overall results, but this may change (maybe) since there are many guilds still trying to go over heroic, once it become more and more a farm content and affliction can get to the bosses with 12 souls. This is mainly because affliction and demo, both are a ST dmg dealer that can cleave a bit onto adds, but since demo has better ST dmg and better cleaving tmg than affly (if adds are stacked), demo pulls ahead. If i was in you situation, i would give a try onto both and choose the one you like more, since both are viable in NH.
About sephuz, just by stunning adds with infernal/fel guard/shadowfury or sileceing with doom, you can do one of those at every boss, except trilliax unless you go infernal or spec demo for an axe toss. I think affly has better synergy with sephuz not only because the UA mechanic, but also if you can get the interrupts for your doomguard EACH (except trillax) boss can benefit you since demo loses to affly on last 2 bosses (not sure if elisande adds can be interrupted).