Yes, you should ALWAYS make sure you keep a second copy of your content(maybe even a third in a different location); either by copying your Kwilt device content via your home network to another drive on your PC or by connecting the Kwilt connected drive to your PC and copying its content to a PC or a second drive. USB drives are electronic devices and are subject to failure. If for any reason the USB drive that holds your content malfunctions, having a second copy ensures that you still have access to a copy of your content.
Some backup advice: Data retrieval costs for a failed drive can be quite pricey, from a few hundred dollars to thousands of dollars. In this digital world multiple backups is essential to the continuity of your files and memories. Everyone has their own horror story of losing a crucial file or all their files, protect yourself against that possibility.