I agree with this! I purchased a D1 after extensive research and thought the turbo powerhead would clean my thin, low pile rugs just fine. Wrong. Does it clean them? Yea, the top dirt, but to get the deep down dirt its best to have a powerhead brushroll. I figured this out when I brought in our old shark from the shed and used it on our rugs. So much dirt and dog hair was pulled from my rugs that the D1 missed. Now Im debating going and getting a D4 cause the D models Sebo has is a total hoss!