iRobot Roomba Max 705 Combo

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.

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.

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 pad slides out along a wall or a kickboard, so the last few centimetres are mopped as well.

The robot returns to the dock during a run to rinse the mop, instead of pushing dirty water around.

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

The dock collects dust in a bin instead of a disposable bag. No bags to buy, but you empty it yourself.

How much the dust bag in the dock holds.

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.

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 recognises 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.

The highest threshold the robot takes, as the maker states it. Measure your own: the step into a bathroom or onto a balcony is often higher.

An extending leg or wheel that carries the robot over a high threshold. Without one it usually stops at about 2 cm.

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.

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

The maker says the robot recognises a pet accident and drives around it, so it does not smear it across the floor. This is the maker’s claim, not a test of ours.

How tall the robot is. It decides whether it fits under your sofa, bed or cabinet.

How much dust the robot holds before you empty it. It matters less with an auto-empty dock, which empties the bin after every run.

How long the robot cleans on one charge, at its quietest setting. After that it recharges and carries on where it stopped.

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

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.