The problem is the import always stops mid-way through. I just keep on starting it over and over again until it finally finishes.
If I reset the site each time the import doesn't finish I will never finish. Literally. It seems to grab some stuff, then time out. Then the next time through it skips over the stuff it got before and gets some more stuff and then times out.
Doing that 4 or 5 times it will eventually finish and you'll get your "have fun" message.
But each time I try this I get most or all of the media files "unattached."
I just tried with a completely new wordpress instance in another domain and 100% of the images were unattached and all the links in the posts went back to wordpress.com.
I think it's just the state of the technology.