Wet cleaning for 3+, will not replace a regular mop. It's more like a function like "beat and collect dust", but not "wash the floors". I have never fallen down the stairs yet, but from time to time one wheel still manages to move out and get stuck, these sounds constantly twitch me. The charge is enough for 80 sq. M and still remains, but there is no water in the tank (when choosing the maximum water flow mode). IN GENERAL: for this price, a normal robot vacuum cleaner suits me, I don’t regret buying it.