Looking at their site, there are two robot vacuums that are $599.99 - the i7 and the 960. When you do a comparison on the site, they list the only difference as

Looking at their site, there are two robot vacuums that are $599.99 - the i7 and the 960. When you do a comparison on the site, they list the only difference as the i7 has more suction, more features, and more compatibility with other iRobot offerings. So why do they even offer the 960? I can imagine anyone who buys that would be disappointed to find out that they could have had the i7 for the same exact price with better features.