This was probably my favorite episode for the twins this season. (Though I have to say that this entire season has been a good one for them. They've had some great moments.) Their dynamics really shine through in this episode and make me appreciate their relationship with each other, which is never dealt with in a deep manner all that much.
I also like the emotional journey that Tuffnut is forced to go through when Macey is lost, with him eventually being willing to sacrifice Macey for his friends and sister. Again, we don't often get much of anything that's "deep" from Tuffnut, so I'm glad this episode exists.
I also loved the final scene, with the twins holding a funeral for Macey and Hiccup standing off to the side rolling his eyes. There couldn't have been a better way to end this episode.