As a long-time Mozy Home user, one shortcoming it had was that every time I renamed a folder or moved files to a different folder, Mozy would need to re-upload all the contained files again.
Now, with Duplicati, I just totally reorganized my backed-up directory structure, and it automatically updated its local database and only had to upload a few small list/index files to the cloud, as the files themselves were unchanged.
Way to go with the 2.0 block mechanisms!