Here is a summary of the differences between Sonata Elite and Sonata III 500.

What Sonata Elite has that Sonata III 500 doesn’t:

• Air intake for hard disk drives on the right panel.
• Right panel is removable.
• Tab for installing a padlock or seal on the left panel.
• Side panels with a plastic layer to absorb noise.
• Blower
• Different hard disk drive installation mechanism that has less contact with the drive and thus reducing noise level.
• Speed controller from rear fan located on the rear panel.

What Sonata III has that Sonata Elite doesn’t:

• Latch for releasing left side panel.
• Two external 3 ½” bays.
• Washable air filter on the front panel accessible from the bottom of the case.