These are the types of solutions that a lot of Permie purists reject. For this I say, use appropriate technology. If you have limited space, are dealing with toxic soil in the concrete jungle or need a high yield per square foot to make an urban garden cost effective… this is a great solution.
For those of you having trouble with my ready acceptance of plastics, unnatural growing systems like hydroponics and the like… keep in mind that I believe the short term goal should be to reduce shipping of food and to decentralize the food system as much as possible and as fast as possible.
This will give people the opportunity to control what they eat. It will also limit the amount of oil products being used in food production, this method removes the oil use from fertilizer, pesticide, shipping, power for storage at warehouse and grocery and for fuel for customer pick up, and replaces it with a to a one time durable good that is the pvc pipe that makes up the garden bed. This type of application of appropriate technology also creates opportunities to grow food in less than hospitable environments. So in my opinion, the ebnefits of these type systems outweigh the negatives by a long shot.