Rest of my team:
Just got off Plasma's frigate and heading to the giant chasm. Saw there were level 47 vannilish in here, but I don't know if I should get it or get a Meinfoo
Well, I would choose Mienfoo based of 3 things:
Type advantages they bring to your team.
Both Vanllish and Mienfoo is super effective against 4 types but only 2 that can't be covered by others in your team.
Mienfoo is weak to 2 types with one shared weakness with Serperior (Flying)
Vanillish is weak to 4 types with a shared weakness with Arcanine (Rock) and with Watchog and Krookodile (Fighting)
Evolution and movepool.
Mienfoo evolves at a staggering level 50 learning 36 TMs and being able to learn 7 types of offensive moves (i.e Fighting, Normal etc.)
Vanillish evolves at level 47 learning 23 TMs and being able to learn 3 types of offensive moves (i.e. Ice)
Against the Elite 4 I would still choose Mienfoo for 2 reasons.
1. Mienshao is super effective against Grimsley which none of your other team members are super effective against with a Stab attack.
2. While using Vanilluxe against Iris may sound good on paper as it's super effective against 4 of her Pokemon keep in mind that 4 of her Pokemon has a move super effective against Vanilluxe while only 1 of her Pokemon has a super effective move to use on Mienshao. This along with the fact that Mienshao is Super effective against 3 of her Pokemon is why I'd choose Mienfoo over Vanillish.
Hope I helped :)
I would use Mienfoo, as its easy to get it to level 50 where it can destroy everything. Plus, Mienshao is fast enough to outspeed Iris' Hydreigon which it can OHKO with High Jump Kick. Then, when it learns Aura Sphere at around level 70, that's when it kicks ass