Despite being one of Vance's more celebrated stories, a re-read didn't really change my view. I'd say it's a 3.5 rather than a 3, but I round down because it could have been better.
Vance starts with an interesting idea (view spoiler) and introduces it in an understated way. But the result lacks the usual Vance narrative charm, and emotionally, the story doesn't go very far. It feels more like a sketch than a full story. It's a shame, because as a novel, I think it could have achieved it's promise.
Certainly worth reading, but if I had to choose a story for which Vance should have won a Hugo, this wouldn't be it.