I think Arrival was quite good, but has some blemishes that Chiang's story doesn't.

To name a few: the movie is way more sentimental -- I subscribe to the notion that "less is more" when trying to stir emotion, and I think Villeneuve overdid it -- and also has your standard "big movie" thriller/suspense/action moments that are completely unnecessary and are only there to make the movie commercially viable. I understand why they are there, but they are still blemishes.

To be fair, some things only work in the movie and are bits of genius, like when Louise suddenly asks why she's getting all these mental images of an unknown girl -- only then the viewer understands she's not remembering something from the past. It's a surprising moment and, to my recollection, it's only in the movie. Even if I misremember and it was in the story, the visual element works better.

The short story is perfect.