- its ability to run batch files after a succefull download (which for example can reset your router and renew your ip)
- an external program which can recognize and automatically fill CAPTCHAs
So if you want to fully utilize it after you download it you need also:
- write or find a batch* file that can reset yout router / connection and get a new ip
- download an anti-captcha or OCR program that can work with USDownloader
More detailed guide and howto for enlgish speaking users can be found here and here (or google for usdownloader reconnect cap).
* If you have problems finding a batch for your router, leave a comment here and I may be able to help you