Cumbersome is one way to put it.

1. You have to export each story individually.. Fine if you only have a few, but if you have a lot of them? This could take a long time.
2. Images are exported as links to Storify's mirror of the image, rather than linking to the original, which means that unless you go through and fix all of the links, the exported images are still going to disappear after Storify shuts down.

I've only got one story to export, and I'm seriously considering just manually replacing it with the individual Twitter embeds instead of using the exporter.