My sister in law has been using a standard size one for over a year,on a regular basis, as they have been using seasonal sites for most of this time as my brother has retired. She raves about it. Having said that, they have a German van without an oven.We met up with them and she cooked a very acceptable meal in it. We then visited Lakeland and decided to buy a large one which we now use instead of our oven as it cooks quicker, cheaper and you can use it in the awning..You could make do with the standard size if there are only 2 of you, but for the sake of the extra we decided on a large one, particularly if you want a full roast with veg.Also saves on the washing up!