Farm Smarts: Double Digging

I decided that I needed an additional garden, specifically for potatoes next year. After reading the digging debate in John Seymour's "New Self-Sufficient Gardener" I decided that double digging would be best for my garden. I liked the fact that you could remove the sod, but just move it within the same plot so you're not robbing the soil of that valuable layer. Double digging is a method of lifting the sod from a trench, 2 feet wide. Then removing the first 5 inches or so of dirt. When the dirt is lifted, you take a spading fork and aerate about 5 inches deep. Then you make a second trench the same width, put the sod upside down in the first trench, chop the sod best you can and pile the dirt from the second trench (again about 5 inches deep) into the first trench. And continue on, using the dirt and sod dug from the first trench and putting it in the last trench. (There's some great diagrams on Google images that illustrate the process.) So that's what I did, anticipating that Id get a lot further than I did. I got 3.5 12 foot trenches completed. So if I work as long and hard as I did today, it should take me 6 days to complete my garden. Weighed with the option of tilling multiple times over several months, Im not sure which the better option is. I guess the fruit of my labour will be the judge. (I better get some mighty big potatoes out of my garden next year!)