Simple: Apple sucks at cloud services. They provide them because it is easier for a subset of their users not to have to think about getting a third-party servi

Simple: Apple sucks at cloud services. They provide them because it is easier for a subset of their users not to have to think about getting a third-party service. Google and to some extend Microsoft want/expect you to do everything in the cloud. Their sync clients are generally less reliable, do not support P2P sync, and do not do block-level sync. Google even syncs placeholders for Google Doc documents, rather than real local office files. Microsoft encourages people to create/open documents directly on/from the cloud (with its standard dialog boxes). If you want to own your data and reliably sync them between your machines, Dropbox is the best choice. And probably they'll continue to be the best, because sync is their product and not some way to funnel people in other products.