The most impressive function I love about this iRobot Roomba 550 is auto docking. The robot could go back to his/her charging station by himself/herself 9 out of 10 times. This is impressive for $300 's. Roomba 550 works on carpet as well as on hardfloors. After our new carpet has been vacuumed it was quite very clean as if we used a regular size vacuum cleaner.

     I'm waiting to buy a more improvement of lower maintenace, larger trash storage and more small spot cleaning's patterns.