Roborock S7 vs Roomba j7+: Roborock S7 wins for hard floors with real mopping and better navigation

The [Roborock S](https://www.amazon.com/s?k=Roborock+S&tag=wehavethat-20)7's sonic mopping actually scrubs hard floors, while the [Roomba j](https://www.amazon.com/s?k=Roomba+j&tag=wehavethat-20)7+ just drags a damp cloth. The S7 also uses LIDAR to map rooms without bumping into things, making it more efficient on bare floors. The j7+ is better at avoiding obstacles and emptying itself, but for hard floors, the Roborock cleans deeper.