The main thing is with the chinese ones you get lidar and a cached map from that lidar run (so you can send it to clean specific areas) and they cost maybe a third or less what roomba charges, at least when I was in the market.
What would they possibly do with my floorplan? It isn't like I am zuck where there might be risk of commandos breaking into my compound... Chances are that floorplan is in some city hall database that they already breached anyhow.