However, there are a few differences. Firstly, Dropbox and SpiderOak seem to be the two file syncing services with the best cross-platform support. I can't find any official Linux app for Google Drive or SugarSync, though SugarSync seems to have the best Android app (with actual two-way syncing of entire folders). However, SugarSync on Android messed up my files quite a lot, forcing older versions to overwrite new versions, and problems like that.
Dropbox doesn't sync whole files if it doesn't have to, sometimes it only changes the updated parts of a file. GDrive only copies whole files, to the best of my current knowledge. I'm note sure about the rest of the sync programs.
SugarSync has the best customization, I think, where you can select multiple folders to sync, at different locations, etc. SpiderOak actually is just as customizable, albeit a lot slower to actually transfer. On the other hand, SpiderOak is super-secure, one of those setups where they can't look at your files, because they don't know your password. Of course, that also means no recovery if you forget it.
Right now I use FolderSync on Android for dedicated syncing of files I edit on my phone and desktop. It works with all the biggest sync services, and it works very well. Very customizable. I won't tell you what sync service I'm using for these files, but it doesn't really matter that much.
Google Drive won't let you choose a custom place to store your files on your computer. Not that I can find, at least. Seeing as how I'm considering a move to Kansas City--for Google Fiber, to be closer to family, etc, I may soon be in a position to make good use of that free 1TB of Google Drive storage. But is Google really expecting me to keep 1TB free on my C: for that?
Okay, Google probably doesn't expect me to actively sync my entire Google Drive to my computer, but on one computer, I probably will. I'd definitely sync all my music on it, all my ebooks, a lot of my work files that just need to be backed up in case of a fire or something.
It's worth mentioning that even though you can't set your Google Drive directory anywhere but in My Documents, you can choose which folders you want to sync to a particular computer, so your netbook could constantly sync your work files but not all your music.
Just thinking about the future, and if I had a 1TB Google Drive, how ridiculous it would be to keep all that space on the C drive.
It's worth pointing out that Windows 7 actually makes it really easy to move any Windows folder in your User directory to a different location. Simply right click, go to Properties and then change it in the Location tab. Put your download directory on your second drive, easy as that. Too bad it doesn't work with third party folders.
Too bad Google Drive doesn't make it at least that easy. I would say that it's probably coming eventually, but Google's main problems in my book are their slowness of updating services and their lack of allowing user customization in general.