The Xiaomi S40 pulls ahead with 4000Pa suction for carpets

Between the Xiaomi S40 and H40, suction is the clear differentiator: 4000Pa versus 3000Pa. That extra 1000Pa makes the S40 noticeably better on carpets, where it pulls out embedded dust and pet hair the H40 leaves behind. On hard floors both perform fine, so the S40 only really justifies its premium if you’ve got rugs or carpeted rooms to worry about.