Allow to import users from vBulletin

I know the documentation says this is not something Drupal VB can do, however there is another module that seems to at least import all of the users into Drupal but probably uses a different approach.
Its called VBulletin to Druapl. http://drupal.org/project/vbtodrupal

I was wondering if I ran this just to get the users into Drupal, would it cause any conflicts with Drupal VB? It also brings over all of the treads and stuff into the forum, but I could just delete all that stuff after the import and keep the users.

The reason I would want to do this is to be able to use Drupal Newsletter modules and stuff like that. I would like to keep using vbulletin, just import the users so i can get their emails in the drupal database.

Thanks!
- Riki