[Lagerfeldt]

Pros of turning off journaling on your audio disk: more speed (higher track count).
Cons of turning off journaling on your audio disk: None really. In case of a real hard disk failure journaling most likely won't help anyway.

Always do regular backups of mission critical data. However, I haven't experienced any trouble with my Macs since I started in 1996.

Here's some Apple info on Journaling:

When journaling is turned on on a storage volume, the server automatically tracks file system operations and maintains a continuous record of these transactions in a separate file, called a journal. The operating system can use the journal to return the file system to a known, consistent state after a failure. This eliminates the need to perform a consistency check on the entire file system during startup.

Journaling is best suited for servers requiring high availability, servers containing volumes with many files, and servers containing data that is backed up at infrequent intervals (nightly, for example).

If a volume contains read-only data that is not mission-critical, it may not be necessary to turn on journaling if performance is more important than safety.