Roomba i3 vs i4: Bigger battery is the only real difference

Regarding the Roomba: The i4’s larger battery extends cleaning time for homes over 1,500 square feet, while everything else — navigation, suction, brush system, dustbin — is identical. The i3 may need to recharge and resume on bigger floors; the i4 can sometimes finish in one pass. If you don’t need the extra runtime, save money and get the i3.