The i3 uses random bump navigation and tends to plow into obstacles and get stuck, while the j7 uses PrecisionVision to see rogue Legos and drive around them.Should I buy a Roomba combo model if I have wall-to-wall carpet?

No, don’t buy a combo model if you have wall-to-wall carpeting because the mop pad can lift but still leaves a damp trail.

Report 007054. Filed.