Earlier quoted context omitted.
Yeah but the real problem, the ones users are trying to solve is the limits on having to move everything into one sync folder. Transparent symlinks are the cheap fix for them so that they can keep their files where they want and still have them sync. The better solution would be to just allow any folder(s) to be synced but none of the major cloud sync providers seem to want to enable that.
Have a look at https://www.cubby.com/ . It syncs existing folders you want to, and per synced folder you can decide to use their cloud or sync directly.
http://help.cubby.com/forums/169907-general/suggestions/3529...