I have plants in a pot on my patio and then I have a spot at a local community garden. This year, my patio potted plants are doing a lot better, they don't grow as fast or have ripe pods as soon, but they are healthier and have bigger pods. I think the clay soil we have here was difficult for the roots to make headway into and there was some disease or pest or something that set the plants in the ground back when I first put them out there.
Try both, see what happens, pots give you more control which is nice if you put a lot of effort into getting them going.