Sharke, from my read, they don't write to your drive casually. The job of Gobbler is not to sync different work environments. That's up to you. It's to BACKUP your work environment and make it easy to share it.
So, if you load up a project and send it to me to add a little something, then I'd load my result to MY Gobbler account, not yours. Then I'd send you a link so you could download it. You could then choose whether to bring my stuff into your project or to replace your copy with mine.
In either case, you should be able to restore to a point in time using Gobbler. So... you over-write your copy with mine. It syncs to YOUR Gobbler account and then you listen and realize I suck! Surprise, Surprise! So you go to Gobbler and download the version prior to me and you're back in business.