Hello together
That is correct. The Roomba s9+ can store up to 10 floor plans and can be used on multiple floors.
It then recognises itself which floor it is on.
However, it has to be brought to the floor manually, because it cannot climb stairs ;)
If there is no charging station on this floor, it returns to the starting point and has to be carried manually to the charging station again. On the charging station, it can then be vacuumed using the app.
Best regards
Your iRobot team

Yes, it can learn several floors. But the automatic emptying does not work.
You pay a premium for the base station. I don't think that's worth it if you have to carry the Manuel hoover to another floor anyway.