I am thinking about purchasing a large oval dutch oven and I would appreciate some advice on the best size to get. I am looking at getting a Staub and they offer two sizes; 5qt and 7qt pots (29 & 31cm respectively). Which do you think would be the more useful size to get? The cheaper option would be preferred but I don't want find out after purchasing it that I won't be able to fit a whole chicken or leg or lamb in it. For other uses it would normally be used for about four portions, so the smaller size is more attractive - but it is more important that it can fit a whole roast in it.
Do you have any advice that might help me make this pricey decision?