I was using Google Drive for a while, and I moved all of my BS files into the locally synced folder.
It worked great, provided:
1. BS only open on one computer at a time
2. After closing BS on one computer and before opening on the second, make sure that GDrive has fully synced between the computers.
Occasionally, I saw a message when loading BS that the software was "still running," and I was given the choice to run anyway or close - I just clicked "Run Anyway" and I never had any issues.
@Brad: Would be a great feature to have recipes sync between all installed instances and mobile, without having to ship back and forth between local and cloud - version control can be tedious with enough recipes.