What I like about the boxes, is that it cuts down on the weeding and the watering and walk around the plants fairly easily. Everything is within reach.
I've just planted another row of peas, beans and carrots seeds today. I think the boxes may discourage a few animals. I keep finding holes, that looks like a dog (judging by the paw prints) may be trying to dig up my sunflowers, which are in the middle of the garden and not in a box.