I have not run across anyone that uses it. One important distinction between the two is that Scribe is Microsoft certified so its product adheres to the SDK when importing data. Since data integrity is the life force of any viable CRM system, I also encourage Organizations to go with certified methods for importing data whether that be Scribe, the CRM Import Wizard, the Data Migration Manager, or writing a custom import process that strickly adheres to the SDK.
Using a different method for getting data into the system will at best leave you with a lot of data issues or worse case, render your application unusable. The end result of both is that the risk for rework and project failure is high.
Best Regards | Twitter: edwardsdna