Hi, Lyman. It's
Dave, actually, not Dan. (Dan Frakes is the guy who wrote the review.)
Anyway -- there is the ability to schedule in the current version: see Section 12 of the User's Guide for the technique to use.
I'm not sure what you mean about "Target Disk Mode" -- you'd really only use that if you wanted to copy to another computer's hard disk directly, as it would basically turn a computer into a FireWire disk drive.
Images are typically used when you can't write directly to a drive. For example, if you want to store a backup on a NAS, you'd use a sparse image, because you can't write directly to a network drive. (A DMG can be created if you plan on restoring it a
lot, such as in a lab situation -- otherwise, the up-front time of converting doesn't pay for itself.)