Clickfree
Thank you for your questions. I had to touch base with the folks at Clickfree to get the answers. Here you go.
Question: Does the C2N just rely on the archive bit being set to snag a file, or does it use a more sophisticated method of determining new or changed files?
Answer: To determine a new file, the C2N software checks the size and date of the file, not the checksum or any specific bits.
Quesion: Does the C2N keep the most recently backed up version of a file?
Answer: Yes, the C2N backs up the most recent version of a file.