Robotic vacuums have come a long way. So, Consumer Reports put three of the latest models to the test to find out if they clean as well as they claim.

Testers set up night vision cameras to show how the vacuums work.  Infrared sensors help get the devices out of tight spaces, find dirt and keep them from tumbling down stairs.

When the bins are full, they stop cleaning and return to their docking stations.

Testers tried them on cereal, sand, rice, cat hair and tiny pieces of paper.

"The Roomba did better simply because it covered all areas of the room several times," said Consumer Reports' John McAloon.

Other models are more systematic, moving in straight lines across the room.  They pass over an area only once.

When the testing was done, Consumer Reports said the $450 iRobot Roomba did the best job. 

Robotic vacuums are easy to program for tidying up, but they can't replace your regular vacuum for deep cleaning.