Some passwords are protected stronger than others. In fact, in our daily life we routinely use passwords that are weakly protected or not protected at all. Instant messenger passwords? Stored in Windows Registry or configuration files in plain text or barely scrambled. Website passwords? Depending on the Web browser, these are extracted instantly or in a matter of seconds. E-mail passwords in popular applications such as Outlook Express, Windows Mail, Windows Live! Mail, or Thunderbird? Displayed instantly with a simple free tool. Older Office documents, third-party office applications, and many other sources may contain passwords that are more easily accessible compared to passwords protecting Apple backups.
It is a good idea to spend some time extracting the easily recoverable passwords stored elsewhere. Add those passwords to the top of the wordlist file used for a dictionary attack, and in some cases, you won't have to deal with lengthy attacks...