Unlike what I've read about other upside down tomato planters, this one from Gardener's Supply looks like a functional product. Note that it has a 1-gallon water reservoir at the top that feeds water via a capillary matting strip. I have not used one, but the engineering looks workable and the reviews are good. It looks like a good product to meet the needs of city dwellers in particular.
I really admire employee owned Gardener's Supply for their long record of innovation. They continuously strive for better growing techniques. I don't know of another company like them.
Check out the following video and see what you think.