They're still one of the only two companies who do differential sync (Dropbox & Microsoft), and the first ones offering that feature. If your upload speed is ti

They're still one of the only two companies who do differential sync (Dropbox & Microsoft), and the first ones offering that feature. If your upload speed is tiny and you're editing a big file, it's great to upload just a few KBs instead of the entire 100MB. I agree their nagging is annoying, but they're still (IMO) the most stable sync client out there.