Dreame L40s Ultra

It empties into a 3.2 L bag and holds 4.5 L of clean and 4 L of dirty water, so most homes go weeks between refills, and the dock cleans its own base.

The robot is 3.8 inches tall, so it slides under most sofas and cabinets, though very low furniture may be tight.

It clears obstacles up to 40 mm, so it handles most door sills and transition strips between rooms.

It runs up to 220 minutes per charge, enough for most homes, and recharges and resumes for larger ones.