I did a course offered by my hospital that was based on DAFNE but was different in that it took place over five weeks (one whole day a week) rather than five consecutive days. I found it incredibly useful. I had been diagnosed in the 1980s and so had been brought up weighing everything - but without being allowed to alter either the amount of carbohydrate consumed or the amount of insulin injected. Aaaah, memories, memories.
The thinking behind the course was that it was felt that participants would benefit also from experiencing using the information between sessions, rather than just having it all in one go, during a single five-day period. And work didn't make me take it as holiday, so that was good - I don't know if they'd've felt differently about it if I'd had a five-day absence all in one go - maybe, maybe not.
I haven't done the five-day version, as our hospital does the course variant mentioned above rather than DAFNE itself, but I found it very useful to be able to make ratio adjustments etc during the days in between, which I could then report back on and which we could all talk about together at the group (the fact that it is a group experience, by the way, was the most helpful aspect of all!).
Mind you, I still remember with amusement a 'discussion' I had on the course with the DSN and dietician about how to calculate the grammes of carbohydrate in a baked potato. I thought I'd test the different maths between calculating it raw, and cooked. Using the equation for raw 'old' potato, and calculating the amount for the raw potato pre-baking, I got a completely different figure to the one I got using post-baking - i.e. the equation for a baked potato, weighed when baked.
I seem to recall that the discussion ended with me saying, rather louder than was perhaps necessary, 'BUT IT'S THE SAAAAAME POTATO!!!!!!!!!!'.
And in that moment I learned that carb counting wasn't perhaps the exact science I had at first imagined....
I'd say go for it - it's very, very worthwhile information, and although I'd 'done' carb counting all those years ago - well, it was a revelation.