Almost all external USB hard drive and USB memory media/sticks come today preformatted with FAT32.
As far as I know the only advantage of the file system is the compatibility among OSes and devices.
Is it reasonable to reformat it with exFAT or even NTFS? How this would affect the performance and security?
Best Answer
Here is an article where extensive testing on usb drives comparing performance of FAT32, NTFS, and exFAT.
Conclusion from the testing:
As far as file system security goes, if you reformat to NTFS or exFAT you will gain File System Permissions on your USB drive. Which I have never had a need for on a USB drive, because I am the only person using the drive and I do not want to limit access to my data.