Good upgrade over the Oral B 1000 if you need the features [SEP] We  have owned different Oral B power toothbrushes over the years with the latest being the 1000.  I have no complaints with the 1000 it works.<br /><br />When determining if one should purchase the 4000 or the 1000, one needs to look at the additional features the 4000 provides.<br /><br />If you have sensitive gums then you will need to purchase the 4000, there is a gentle mode.  Additionally, I would not recommend purchasing the floss action heads if you have sensitive gums.<br />While there is an in handle display in the 4000, it is not a digital display.  It is a light next to the feature you are currently selecting<br /><br />I do not see any difference when using the polishing mode in the 4000, however, I do not have stains to determine if the feature works.<br /><br />The one annoyance for me with the 4000 is that I accidentally change the mode instead of turning off the brush from time to time because the button are close enough to do this.<br />While I recommend the Oral B 4000, I would suggest using the 1000 if you do not have sensitive or stained teeth.