Its syncing is more flexible
Google Drive creates a new folder, named \Google Drive, on your computer, and to have files synced to the cloud and other devices, you move or create files or folders there. Those files then always sync to the cloud and any other devices on which you've installed Google Drive.
But what happens if there are folders that you don't necessarily want always stored in the cloud and synced to other devices? With Google Drive, life gets complicated. You'll have to move that folder out of Google Cloud when you no longer want it synced, then move it back in again when you want it synced again. That's too much work and too prone to problems.
SugarSync makes it much simpler. It doesn't add a new drive to your computer. In SugarSync, simply indicate which folders you want synced, and they get synced. When you no longer want them synced, tell SugarSync to stop syncing them. That's much easier than with Google Drive.
It's better for people with multiple devices
I've got a PC, Mac, iPad, Android phone, and Xoom tablet that I use regularly and on which I frequently want to see documents and files that I'm working on or have archived. But I don't want all folders to sync to all devices, and in some instances I only want the folders stored to the cloud and not synced at all.
Doing this in SugarSync is quite easy; it's built right into the product's workflow. Just indicate which folders you want synced to which devices and you're done.
It's possible to do this in Google Drive, but not nearly as easily -- and not as completely. By default, any folders you put into your \Google Drive get synced to every device on which you've installed Google Drive. On a PC or Mac, you'll have to dig down and find the Google Preferences screen, then indicate which folders you don't want synced to that device.
As for Android devices, I haven't yet found a way to tell the Android Google Drive client not to sync certain folders to it. It's possible that there's a way, but I simply haven't been able to uncover it yet. And there's not a Google Drive client available yet for the iPad, so it won't work on that device yet.
It lets you keep your existing folder structure
To sync files and folders to the cloud and then to other devices in Google Drive, you have to create new folders under the new \Google Drive folder. If you already have a logical folder structure in place, this can make a well-ordered existence confusing. You'll have to create some folders in your normal folder structure, but put others in the \Google Drive folders if you want them synced. So if you organize folders by your customers, for example, you may need to put them in different locations, depending on whether you want the folder synced.
That makes no sense. With SugarSync, you keep your existing folder structure. When you want a folder synced, you simply tell it to sync -- no other action is required. And if you want it to stop syncing, just tell it to stop syncing -- no need to a different location.
Note: For more information about Google Drive, check out my look at it: Google Drive review: Adding cloud storage to the mix.