Amazon has already reduced the price of six Roborock robot vacuums with the Prime Offers Fest approaching, according to ABC España. All six vacuum and mop floors, so what sets them apart is the base — the station each robot returns to in order to charge. The work left for the owner depends on that dock.

The article describes a fairly clear ladder. Without a self-emptying base, dust stays inside the robot's tank and has to be removed by hand. With one, the robot deposits the dust into a bag and the owner can forget about it for weeks.

The next step up concerns the mop. The most complete bases wash it in hot water and then dry it with air so that it does not stay damp until the next cleaning pass.

Because each rung costs more, ABC España advises deciding which level of dock you need first and only then looking at the size of the discount. It suggests starting from a practical question: how many times a week are you willing to bend down to empty the tank, rinse the mop or pull tangled hair out of the brush? That, the outlet says, is where one robot separates from another.