I’ve been storing my Scrivener projects in Dropbox since day one (with the recommended change of auto-save to every 10 seconds), and this has always worked perfectly, syncing within seconds and allowing me to stop work on one Mac and pick up where I left off on a second one.
Back in May, I decided to switch my cloud drive from Dropbox to Google Drive, as you get a lot more space free, and paid options are a far better deal. I’ve been using Drive exactly as I did Dropbox, but while absolutely everything else syncs fine between the two Macs, my Scrivener project doesn’t. It hasn’t ever updated.
I searched and saw a few generic comments about issues with Google Drive, but nothing concrete. Can anyone shed any light? For now, I’ve gone back to Dropbox.
I don’t think your method is a safe way to synch,
Because of the multi-file structure of a Scrivener project.
Instead of hoping that timed auto-saves will work,
I’d ZIP the file before backing it up.
The Backup command has a checkbox for this purpose.
Do that, and GDrive should have no problems.
10 seconds is the interval recommended by L&L.
I do zip the backups, but I’m referring to the live project, not the backups.
I don’t know any specifics about how the synchronization works for Google Drive vs. Dropbox or any others, but we have found that Google Drive does not play well with Scrivener’s multiple file format. Keeping zipped backups there is fine, of course, but for live projects, I’d stay away from GD for now. We had to post an advisory against it and Microsoft’s OneDrive (formerly SkyDrive) as a number of users have reported issues trying to sync live projects with those services.
Dropbox has a much better history working with Scrivener. I know a number of users have spoken well of Cubby for storing live projects; that’s another free option if you wanted to get away from Dropbox, although I haven’t used it myself and don’t know what specifically it offers.
Thanks, Jennifer, looks like I’ll be sticking with Dropbox, then.
It’s just a bit of a mystery as to why GD doesn’t play, as it syncs everything else flawlessly.
Ben
As a user of both Dropbox and Cubby:
Cubby gives you 5GB free space, in comparison to DropBox’s 2GB;
Dropbox reserves a folder on your hard drive the same size as your allocation on the server and everything you wish to upload has to be within that folder … my wife has upgraded her Dropbox to 50GB which she would like to share with me, but on an MBA with 250GB of SSD, I haven’t that much space to allocate to allocate;
By contrast, Cubby doesn’t reserve space on your hard disk, but you choose which of your folders you wish to designate as “Cubbies” … they can be any folders anywhere on your disk, even on an external HD … and how much space is used on your HD is determined by how much you put in them with a total limit being the space you have on the Cubby server.
Never had any problem with Cubby, other than that when I put a short video in one of my Cubbies, it could be downloaded by the friend to whom I gave the link, but not streamed from there. Dropbox allows streaming (but beware, if too many people try to access it, your daily site-traffic allowance can be exceeded and it will be blocked).
Mr X
PS If anyone would like to give Cubby a try, use this link and we’ll both get extra space. 
cub.by/i/01_D6dC4rvl_4B
Edited once for infelicitous wording.