Not that I would know any better but I always saw a user-controlled approach built around rdiff as a better alternative than surrendering files to a non-transparent third party such as Dropbox (who, go figure, used librsync originally).
I am aware of another project called "rdiff-backup", also at nongnu.org:
rdiff-backup backs up one directory to another, possibly over a network. The target directory ends up a copy of the source directory, but extra reverse diffs are stored in a special subdirectory of that target directory, so you can still recover files lost some time ago. The idea is to combine the best features of a mirror and an incremental backup. rdiff-backup also preserves subdirectories, hard links, dev files, permissions, uid/gid ownership (if it is running as root), and modification times. Finally, rdiff-backup can operate in a bandwidth efficient manner over a pipe, like rsync. Thus you can use rdiff-backup and ssh to securely back a hard drive up to a remote location, and only the differences will be transmitted.
Yes! I use this and like that it's so simple, and that the latest version of the backup is easily available as plain files. (Any metadata that the filesystem doesn't support are stored separately in files, so it works across different type of filesystems and operating systems.) There is even a FUSE filesystem, "rdiff-backup-fs", for mounting the whole backup history, with each backup point in a subdirectory of its own, like it should be!
Unfortunately, it seems not to be developed any longer, and it has a few things that would need ironing out:
* You can't pause a backup and continue later.
* Some operations (notably recovery after an aborted backup run) is excruciatingly slow. It takes tens of hours for me with a backup of 40 GB or so (on a low-powered computer as server, though). I think rdiff-backup-fs is resource hungry as well, which is perhaps partly understandable, since it has to go through a series of reverse diffs to present old versions of a file.
* I tried it on Windows once, and it could apparently not handle paths longer than a few hundred characters (due to using that older Windows API, whatever it's called).
* You can't delete intermediate backups, only the oldest one.
There is an elegant simplicity to rdiff, IMHO.