Selective Folder/File Sync for Each Connected Device

CC File Storage and Sync should allow the user to select which folders and files that will be downloaded to each device. Without that, every device you use must have enough storage space to download all files. (e.g. a laptop with over 1TB storage).
Also, this means that the user can not control what content goes to which device. There is no way to separate work from personal content using CC Sync.
Dropbox and SugarSync have been doing this for many years. It is a solved problem.
Unfortunately CC Sync works in only the most basic and simple user scenarios and the everyday world is more complicated than that.