I should've written this before my memory faded.
While I've heard complaints that there's no story here, not even in the story-in-the-story, or the story-in-the-story-in-the-story, I was pulled along regardless. I thought the SF story started out really strong; the description of the alien world was beautiful. I wanted to read that!
The actual story worked very well for me. I think it's the way that aging Iris was portrayed. The parallels between her current life and my grandmother's really struck me, and I couldn't wait to hear more from her.
As always with Atwood, the writing was beautiful, without feeling overly contrived.