I ultimately don't really trust anything that's not a plain file copy or optical disc (a full disk/partition image also works but it's more annoying to mount and access, especially on Windows, and considerably less efficient)
Vista/7's backup (and deja-dup for Linux) wrap things in archives making manual (and/or cross platform) restores extremely annoying, which I consider a very serious downside; 8/10's fixed it but it still uses an annoying folder scheme (and, I think but haven't verified, doesn't use hard links to save space wasted by unmodified files between backups)
Apple's Time Machine was the only pre-made solution I mostly liked, and even then it had its potential improvements...