Overall NH in 7.2 - Play what you like:
https://www.warcraftlogs.com/statistics/11#dataset=90
As of 7.2.5, MM is the strongest hunter spec in Nighthold overall:
https://www.warcraftlogs.com/statist...aset=90®ion=3
Is it far enough ahead to abandon your current spec for it? No.
Does it even matter to 90% of posters on mmo-c? No.
Does it translate to ToS performance? Not yet.
Are sims based on patchwerk and not representative of hectic mythic fights? Yes.
TLDR; stick to whatever your currently playing, the difference is small enough that individual performance, experience and optimal gearing will out weight what a sim dictates should be the higher theoretical dps.