PADI (Professional Association of Diving Instructors) is the worlds largest dive organisation and is present on the market since 1966. During this time accumulated knowledge and experience is hard to beat.
You might say, and certainly old tech divers will do, that other organisations were teaching rebreather diving for longer. Yes, that is true, PADI is giving more time to review the courses and they leave time to observe the mistakes of others to learn from them, and do not repeat them. Whenever the best methods are collected, the necessary knowledge accumulated and the first class materials are available, then this is the time to lunch the course. There is no one who would and could state the the PADI materials are not the best on the market.
The CCR courses are performance based and concentrate on the divers needs to dive safely. The history and other information you might find interesting about rebreathers are not part of it. This things you can look up for free on internet 🙂
The requirements an instructor must meet to qualify for rebreather instructor training and be able to teach these courses are very high too, so you can be sure that you will get a quality training.
The training is also monitored by PADI to ensure the high quality of education. No other organisation does that!
More information on the PADI CRR courses itself can be found here.