We succumbed and had go with the allotment's rotivator to turn over the spud beds. The thinking was that I really just wanted to see what the difference was, and to conduct a bit of a comparison test between that and digging each bed by hand. Firstly I was totally girlie and was rubbish at using the rotivator, so Hubby took over and sent me home to make lunch while he did it.
A few weeks on (Sunday) we came back and checked through the beds for weeds and marked out the beds. We also spread a whole load of well rotted manure on them all ready for the worms to do their job. Overall it WAS a fast way to turn over the earth for the only time I plan to do it so deeply, but will probably not bother again.
We also put a few of the large slabs that were going spare next to our plot to see how heavy they were for when we run them down the side of our plot and hopefully down the middle too. I can't wait to have paths etc. It'll look great!