What I would like to have is the ability to browse my entire file repository and "pin" certain files to make sure I can have the most critical stuff offline, while other files would be streamed when I need them.
I kind of hoped that SpaceMonkey (now Vivint Smart Drive) would be the answer for me and have one sitting right here. It's a a pretty cool device in theory, but in practice, it is extremely slow, backed by a company that could not care less about the product it has acquired.
Then there is Dropbox Smart Sync. This seems promising, but only is available for business users. I don't have any experiences with it.
Still looking for one single product to this right. Am I the only one frustrated with this?