What would you ask before buying a robot vacuum or mower?

Robot Finder launches tomorrow. It matches robot vacuums, lawn mowers, pool and window robots to your home using only what the makers publish, and every option shows how many robots it leaves.

Before launch I'd love to hear one thing: what question do you wish a robot finder asked you? For me it was "will it fit under the sofa" and "can it climb my door sills". If yours isn't covered, I'll look at whether makers publish the figure to answer it.