So this review focuses on the need for an additional charging base and assumes you liked the Neato Robot vacuum enough to buy it. The Neato vacuum robot (we have the D7) is very sensitive to starting from the same spot. So if you need to move the base to different places, you need to place it in the same place. Before we bought a second charging station, I took a picture and marked it with tape as I moved our single charging station up and down the stairs - no fun. Instead, I just leave the charging dock against the wall (we secure it with double-sided tape so it doesn't accidentally move or someone accidentally kicks it when the D7 is docked). It is recommended to purchase a second charging base to minimize docking or starting point issues when using the vacuum cleaner. The vacuum cleaner can be easily moved up and down and placed on different bases.