Higher-end Roombas vs budget Roombas: Mapping models clean smarter, budget ones still bump around

The key difference is navigation — higher-end models (i3, i7, j7, s9) use camera or lidar mapping to clean in neat rows and allow no-go zones, while budget 600-series models still rely on the same bump-and-run algorithm from fifteen years ago. Both eventually cover the floor, but mapping models are faster, miss fewer spots, and can be directed — worth the extra cost if you want intelligent cleaning.