I've already got a charger for the Galaxy Tab 10.1 and I'd like to be able to use it charge both that and a Samsung Galaxy Tab 2 7". It seems to work, but I was wondering if there is any sort of disadvantage to doing that.
You only need to make sure that the chargers produce the same about of voltage and current. There shouldn't be any issues with that.
In my opinion there is no harm to your device if the charger produce the enough voltage to charge the device. You have to keep in mind that the charger should not be low power producer as your device needed otherwise it will be harmful for that, but if the charger produce the same power or higher then it will be fine for device because if the charger produces high output voltage your device will only take how much it need.