I have one remaining problem with GoogleDrive+Insync:
The above solution only syncs at the root Google Cloud Drive. Ideally I could select which Google Cloud Drive folder to sync with my external folder.
They have this implemented!
However, using Insync I was averaging 5GB per day, uploading to Google Drive. I tried Goodsync, and I have already uploaded 25GB in less than one day. If you don't have a lot of files, Insync would probably be great for you.
Compared to Insync, Goodsync is not as intuitive. For one, you need to find the Browse button, to select an online service, perhaps because they are trying to push their own Goodsync connect? After that, the interface is a lot like FreeFileSync, or other file comparison tools, which may not be easy for a newbie. Unlike traditional file comparison tools, Goodsync is capable of accessing FUSE (Filesystems in Userpace), like online storage services.
I have yet to try other sync implementations from online services (like Koofr), which sync to online storage services. Owncloud could be awesome, but it a royal PITA to set up, and they sync options are very poor (I want to be able to exclude directories, and I can't use symbolic links in a folder to achieve this, because they decided to not support symlinks after 1.5x). Owncloud has a very confusing and dangerous interface: https://github.com/owncloud/client/issues/2404. Never mind that it says the issue is resolved: it isn't. They just changed to wording to make it more clear. They don't understand that people are looking to exclude certain folders from backing up to the server, not delete them off their drive. The intention of Owncloud is to keep all files on the server, and only choose certain ones to have locally, but that isn't always what you want. I have a long standing way of organizing my files, and I don't plan to reorganize them for Owncloud.
[Edited by mekineer, March 22]