I use both Jungle Drive with Amazon Simple Storage Service and Syncdocs. I use Syncdocs to sync multiple Google Drives to my local hard drive. I use Jungle Disk for a one-way back-up of my local Sync-doc folders, as well as other date to Amazon S3. Syncdocs is the ONLY service I've found to help me sync multiple Google Drive accounts to my local computer SIMULTANEOUSLY while logged into a single MS Windows account.
I think it is business ready IF you understand exactly what it does with your files and how the various configuration options affect your files. It isn't as simple and fool proof as Google Drive, but it gives you a lot more control. What you will want to avoid is converting between MS Office and Google Apps formatted documents. This is trickier in Syncdocs than in Google Drive.
In Google Drive, it is simple to distinguish native Google Apps docs from, say MS Office docs. They'll have extensions like "*.gdoc". The problem is that Google Doesn't provide an offline tool for editing those documents. They are just links to the document online. If there was an EASY way to open native Google docs offline, then I would guess that Syncdocs would provide an option to download your Google documents in their native format.
This is the main issue with Syncdocs. You are changing the file format of your Google documents so they can be backed up and edited on-line, but round-trip conversion can get wonky, especially if you try to do a lot of editing in MS Office, adding formatting and features not supported by Google Docs.
If you are mostly working in MS Office, set it to not convert to Google's formats, then it works quite nicely, with versioning, etc. You won't be able to edit on-line, but if you wanted to edit MS Office document natively on-line you should be looking at something like Skydrive instead.
