I did the BERTIE course as it came up quicker, I was on the list for it and DAFNE and the waiting time for DAFNE is about 3 years in my Base hospital so it just went to a different location,made no odds because it's the same trust. I did my pump course with people who had done both and one who was type 2 and did DESMOND, made no odds, we all know the principles just talk about things differently elone example; I was taught to count CPs where as DAFNE does 10g. I interchange now when I'm speaking about it. Other slight differences but nothing that has either hindered or helped in comparison to other patients.
I think the most important thing is 1. You and your willingness to learn and engage with the course and it's principles and 2. The teacher! I know all of the DSNs, dieticians and consultants because they are all my colleagues! But there are definitely better teachers than others in a big bunch. Not disparaging anyone it's just that some people are better at "classroom" work than others.