1. I'll have to echo @@Wind Chaser here. The pacing of this episode was all over the place. It comes across as wanting to put in a lot of content, but it got squashed to fit the twenty-minute time slot. Unfortunately, this hurts the comedy quality. Pinkie's narrating joke was good the first time, but it started to get stupid midway, and it felt like a contrived reason to push the episode forward.
2. The yaks are primitive, spoiled, clichéd jackasses. The second they didn't get one thing they want, they started destroying the entire landscape. It's one thing to be upset, it's another to vandalize. These two-dimensional vikings don't deserve to be tolerated, embraced, or celebrated. Instead, Twilight, Pinkie, or some other member of the Mane Six should stand up to them and call them out for their bullshit, not reward them for a party they clearly don't deserve. By rewarding them, the moral loses credibility.
3. I was never a fan of this then, and I'm still not. The geography traveling wasn't given any level of respect here. It won't take an hour or two just to get to TCE or Yakyakistan. TCE is incredibly far north. It would take several hours to get that far. Be more consistent with your geography.
4. Nonetheless, the Mane Six deserve plenty of credit for their patience. Twilight and Pinkie are quite a bit alike, especially their hyperventilating sides. It was great to see Twilight in Swarm of the Century mode again while still keeping mind of prior continuity. Pinkie's admirable actions to give the yaks the perfect party shows her dedication to her passion.
5. Unlike last week, the moral actually connects with the rest of the conflict.
   

In short, WAY better than last week's. But it still doesn't make it good. At most, it's average.

Source: S05:E11 - Party Pooped