iRobot Roomba S9 vs iRobot Roomba j9+

The iRobot Roomba S9 and the iRobot Roomba j9+ each have their own advantages. The j9+ is ultimately the smarter device, boasting a real-time hazard identification system and dirt sensors that allow it to prioritize areas that see heavier soiling. That said, neither system works perfectly. Conversely, the S9 does a better job of actually cleaning, thanks to a more powerful suction motor that's more effective in lifting away heavy debris.