Higher-end Roombas map in neat rows — budget models still bump around

There are two completely different navigation systems in the Roomba lineup, and the price gap comes down to which one you get. Higher-end models like the i3, i7, j7, and s9 use camera or lidar mapping — they build a floor plan, clean in neat rows, and let you set no-go zones so the vacuum stays out of the kids’ play area.

Budget models like the 600 series still use the original bump-and-run navigation: go straight, hit something, turn, repeat. It’s the same algorithm iRobot shipped fifteen years ago. It works — it will eventually cover the whole floor — but it takes twice as long, misses spots, and can’t be directed. If you want a vacuum that cleans intelligently rather than randomly, the mapping models are worth every extra dollar.