One final clarification. I know in this instance I presented the scenario as "friends overseas". I used that scenario because that was the one currently fresh in my mind, as they had contacted me quite recently. But this issue has indeed cropped up for me a number of times in a professional environment as well. I'm sure you have end users who use FTP.

Finally, I like the edited question. I will refer back to this when asking future questions here. Thank you for your time and help!

The end users are in this case non-technical, despite being in a professional environment. For example, I deal with customers every day in a professional setting that have no idea what rsync is, and have ZERO interest in learning. Ie, they want to stick with something they are familiar with, such as FTP, and will in fact get quite angry when another option is put forward. I'm sure you must have experienced similar things! :)

Thank for you the very detailed response! I appreciate it, and thanks to this response I learned a lot about what is expected here on Server Fault. This in particular: "plus I don't know how to get rsync working on Windows" I wanted to respond to. It wasn't necessarily a matter of me learning how to do or not do something, as I am always interested in learning! I should have added more clarity to that statement, the real issue is that even if I learned how to use rsync, trying to communicate how to get that set up with an end user who does not speak english would be a difficult task.