The popup tooltip for the Metro 25 says "Max capacity 25". When you try to create a seating configuration for it, it says "Max 21". But the configuration page will only let you put 20 seats in it, even though 21 is in the dropdown. If you select 21, it reverts to 20 and if you click "Set to max" it sets it to 20.
So which is the max seating? 20, 21, or 25?