Model / bucket size: Some versions say “big size”, “dual wheel drive” or “bigger bucket” which might cost more.
Accessories: Does it come with extra mop heads? Is the handle adjustable? Some listings mention these.
Wringing mechanism: Make sure it performs well (spins/rolls without much effort) so you avoid excess water on the floor.
Suitability for your floor type: If you have delicate wood or specific flooring, verify the microfiber head is safe.