I have been using an impeller style but did not feel the clothes were getting as clean.  Now, I have one that has an agitator and uses enough water to cover the clothes so they ALL get wet--that was not always the case with an impeller.  The only change I would suggest is a setting that allows me to choose each function instead of all the choices preset.  But even that is NOT a game changer as the settings seem to be working for the most part.