Dry-sweeping robot vacuums vs wet-mopping robots: Combo wins for hard floors, skip for carpet

Dry sweeping handles daily crumbs and pet hair; wet mopping tackles the invisible grime film on hard floors. Most combo robots alternate between the two, but the mopping is a light damp wipe, not a deep scrub. If your home is mostly hard floors, the combo is worth it. If you have carpet wall-to-wall, skip the mop and invest in better suction.