Wirecutter's pick when you want oscillating cleaning at a lower price than the Pro 1000. Fewer features but the same core cleaning technology.
If the Pro 1000 is ever out of stock or on sale for less, the Pro 500 is a legitimate step-down that doesn't sacrifice the cleaning action that makes Oral-B great.
“If you want an oscillating electric toothbrush that's typically less expensive than the Oral-B Pro 1000: The Oral-B Pro 500 is the model to get.”