One of the coolest features of Dropbox is block-level sync. Works wonderfully well with encrypted containers (not needing to upload the whole thing when you cha

One of the coolest features of Dropbox is block-level sync. Works wonderfully well with encrypted containers (not needing to upload the whole thing when you change a file in the container). I know Google Drive & Skydrive don't have it. Don't know about iCloud.