I used this extension as an alternative to Jupgrade to migrate my 1.5 site to 1.7 since Jupgrade also migrates useless 1.5 extensions that you can't get rid of except by editing your database. It worked perfectly. All I had to do was export all my articles and set it to also export users and images and then use the import tool on the 1.7 site to import the .xml file and, like magic, it structured all my categories and put the articles in where they belong. The only con is that it doesn't export modules or menus but those are easy enough for me to rebuild, so I'm not concerned about that. This is a great way to perform a clean transition from 1.5 to 1.7.