The developers promised me this would work smoothly, but I spent nearly a month with their support team (who are quite slow to respond), and it still didn't convert my qTranslate database.
In the end, they manually converted the database for me (by which time it was no longer up to date, so I had to manually transfer over several days worth of entries.)
And, worst of all, when we finally got my site up and running with WPML, it was about TWICE AS SLOW as qTranslate.
You can see the results of my testing here: http://wpml.org/forums/topic/slower-than-qtranslate/
And the thread for trying to get the importer to work and the issues I had here: