We've got one. It's a very small one since we take it in our Class B. Our model is the Campfire. We can use it to cook over and just have fun - using mostly twigs and sticks to burn. We didn't buy any accessories.
They really do work as advertised - I actually first saw one on a youtube channel where the guy was cooking over it using a tripod and cast iron dutch oven - it was a Ranger.
They are well made from stainless steel and engineered to be pretty much smokeless. The way the air is fed into them is unique and you can have a roaring fire within minutes. Then when there are just cold ashes left you tip it over and dump them out - that's it for cleanup.
Don't know any cons...