Recs.
Updated
Specs
Pros
Pro You can limit the area that the robot cleans
A small battery-powered device called "virtual wall" allows you to create a virtual boundary that the robot will not cross. It emits an invisible infrared ray 7 feet long that serves as a stop-sign for the Roomba. So, for example, if you don't want the Roomba to wander into a room with your pet's food and water, or a bunch of wires scattered on the floor, just place this device in the doorway.
Pro Works on carpet & hard surfaces
Not only does this robotic vacuum cleaner do tiles, hardwood, and whatever other hard surface you might have as your floor, but its the ground clearance lets it climb onto carpets and clean them perfectly. This lets you get dog hair, crumbs, dirt, and other debris out of that carpet you spent so much money on.
Pro Rubber dust collectors are easier to maintain than bristles
The Roomba 880 uses rubber dust collectors to pick up more dirt than the bristled ones on lower quality models. Not only do they effectively do that, but they are much easier to clean, as you don't need to comb anything out of the collectors, you can just pull everything off in one motion.
Cons
Con High price
Think of this product (and the iRobot brand as a whole) as the Apple of autonomous cleaning robots. It's somewhat over-priced when compared to its competitors - especially for a mid-range product - but it offers superior build quality and the guarantee of quality that can be offered by a company that has been around longer that the competition. Still, the cost is high for someone wanting to test the waters of robotic vacuum cleaners, and a brand doesn't justify it.