When we first got our allotment, the neighbouring plot had the no dig bug. She insisted it was the way to go, so I have had one 16x5ft bed strictly for no dig over the past five seasons. The only crops that seem to benefit is lettuces, and other shallow rooted, quick maturing crops. They really do flourish, but they do everywhere else as well.
Long term crops, such as sprouts, leeks, parsnips etc etc always get off to a decent start, then slow down a fair bit in comparison with the other beds. To be honest, the no dig bed has probably had more organic matter added over the years than the dug beds, but still don't out perform them.
I have visited a garden charles dowding helped set up and mentor, and to be honest, although it's always nice to see veg growing, however it's being grown, it didn't strike me that anything was really growing super well.
Charles himself states on his site that the cropping differences between his dug and undug beds is negligible, so I always find it funny, when people who have been trying it out for a season or two, state the massive rise in crops they now get and the perfect way in which everything grows, as opposed to when they grew veg more traditionally.
Of course everyone has there own ways of doing things, I NEVER dig between November and march, real damage is always done to the soil during work at this time of year no matter how hard you try to be careful. Thick mulches of smashed up leaves, then well rotted farmyard manure is spread thickly over the soil during winter, thus protecting the soil surface from winter erosion. It's then turned roughly in, about early march time, so that all these ingredients are where the roots can get at them over a whole season.
This rough turning of the soil also opens the ground up so the birds can get at any unwanted soil Bourne pests.
I now earn my living by growing top quality veg for a busy hotel, and there is no way I could consider No Dig to do it. In the past five years, my experience is that well prepared soil, treated specifically for the crop that is to follow, will outperform any other methods I have had experience with. I'm not saying all this to put anyone off doing things one way or another, just to put a realistic spin, on a usually unrealistic thread....
Totty