I did the Dafne course 2 years ago. Here's what I liked about it:
It's well-organized and comprehensive. We had people in the course who'd had diabetes for 30 years and people who were diagnosed three months ago, and all of us learnt something new.
It isn't just about food. We also covered some of the many other things that can affect your blood sugar. So on one day we had a practical session testing out the impact of exercise. Another day there was a ladies-only session where conception/pregnancy issues were covered. I kept hinting we should also have an alcohol session but sadly that chapter was strictly theory only!
It was a safe, confidential, supportive environment. Before going on the course, I hadn't had contact with any other T1s. But the first day, sitting around the table for lunch, we all got out our testing kit and pens/vials and I felt so liberated.
I was the only one on my course who was low-carbing. The good thing is, Dafne doesn't preach. Having heard horror stories about dietitians pushing high-carb diets, I'd gone in prepared to defend my heretical low-carb ways. This turned out to be unnecessary as Dafne doesn't tell you what you should eat. It just gives you the tools to make choices.