Old, grey-headed guy checking in . . . okay well, I'm 54 and used to twist wrenches for a living, so you sorta get the picture. Started using BTSync a few months ago and have virtually abandoned Dropbox, except for a couple of shares with work colleagues. I'm syncing many dozens of gigs of music, playlists, pictures, software and personal and work files between my machine, my office machine, wife's machine, a couple o' laptops and two smart phones, using separate synced folders for different sorts of files. I'm not syncing all folders between all devices; each machine only gets what we're using that particular device for. I love it. Even found that it works just fine in virtual machines, easily zipping stuff between the real and the virtual. I'm fixin' to build a home NAS using FreeNAS and run Sync on it, leave it up 24/7 so all my stuff will always be available, even during those mad business dashes three states away on weekends. Fire up the laptop in my hotel room and it's updated in a minute or so. Awesome. Sync will hammer in five minutes what Dropbox would take three, four hours or more sometimes. Also using it to transfer TrueCrypt containers. The only snag is that you have to unmount the container before it'll sync, so I pared the data in the containers to stuff, which while important, we don't change very much. So long Dropbox. I hardly knew ye. Highly, highly recommended.