In looking for alternatives, I came across a very helpful article covering 7 options and their features. The author even put together a comparison table with free and paid storage amounts. http://beebom.com/2016/02/copy-com-alternatives
Other possible options I have come across and have just begun researching are:
Sync by BitTorrent (control access on folder by folder basis)
Seafile (for self-hosting?)
Box.com (10gb free, 250mb file size limit)
Phydio (for self-hosting)
Syncthing (peer-to-peer; cannot share links with others)
FreeFileSync (beware - some installer files out there bundle extra software)
File Synchronizer at karaosoft.com
This is by no means all the options out there. Does anyone have experience with any of these choices (good or bad), and have any comments regarding some of their features? Free or paid, peer-to-peer or cloud, self-hosting, cross platform, etc.
Thank you to everyone here offering suggestions.