Traditional food as in not hothouses and pesticide laced chemical food...Hmmm... I guess disadvantages would be that you cannot have any one food at all times of the year because it's not in season. The food has to have more care taken with harvesting and it makes the food more expensive for the consumer.

The advantages are better tasting food, less harmful chemicals and pesticides, and the need to store food for a year or more before it's artificially ripened and eaten.