iRobot Roomba Max 715 Vac+

Suction in pascal, as the maker measures it. More pascal helps on carpet, but it says little about how well the robot picks grit off a hard floor.

A brush that guides hair to the side instead of letting it wind around the shaft. It saves the cutting work in homes with long hair or pets.

The robot notices when it drives onto a carpet. Most then raise their suction, and a mopping robot lifts its mop or leaves it at the dock.

Whether the robot copes with pet hair: a brush that hair does not wind around and a dock that empties the bin for you. Where the maker does not say so itself, we read it from those two.

A sensor notices where more dirt lies, at the doormat for example, and the robot cleans that patch longer or a second time.

How the mop is built: flat pads, two spinning discs or a roller. Discs press harder on dried-on dirt, a roller rinses itself while it works.

The dock empties the robot’s dust bin, usually after every run. You only empty the dock’s bag or bin.

How long the maker says a dust bag lasts with daily use. With pets or a lot of carpet it is shorter.

The dock washes the mop for you, so you do not rinse it by hand.

The dock dries the mop afterwards, so it does not sit there wet and start to smell.

Drying is done with warm air instead of cold. It is faster and it helps against smell.

The dock mixes detergent into the water itself, from its own bottle.

The dock can be connected to the tap and the drain, so you never fill or empty a tank. It does need a connection nearby.

How the robot maps your home and follows that map. Lidar measures with a laser and works in the dark, a camera looks along and recognizes more.

How the robot sees loose things on the floor, such as cables, socks or a pet accident. A camera with depth sensing sees more than a bumper that reacts on contact.

How many floor plans the robot keeps. With more than one it knows which floor it is on when you carry it up or down the stairs.

How you keep the robot out of a place: a zone you draw in the app, a virtual wall or a magnetic strip on the floor.

Whether the robot has a camera, and what for: to recognize obstacles, or also to show you a live picture of your home in the app.

You pick one or more rooms on the map in the app, and the robot cleans only those.

The capacity of the battery. It hints at the runtime, but how much the robot draws counts just as much.

Which voice assistants the robot works with, such as Google Assistant or Alexa.

You set days and times, and the robot starts by itself, also when you are not at home.

Whether the robot works with Home Assistant, the home automation software you run yourself. Official means the integration comes with Home Assistant itself, community that volunteers maintain it.