I've experienced some slight differences between the two editor themes of Query Wrangler. When I have Drupal Views-theme activated, there seem to be some fields missing. For example in the Tabs-theme I have the label text field and a field for rewriting the output under the "Fields" tab. In the Drupal Views-theme these fields are missing.
Another issue is, that under both editor themes the preview query function doesn't seem to work anymore.