I attended both CSM and CSPO trainings. Both give you really great amount of information about Scrum and Agile and both were the best trainings I have ever attended but also the most expensive. I'm not sure if certification itself has any higher meaning then "yes, you attended the training".
Reasons why I think these trainings are good:
- It will give you very big amount of practical information about using Scrum
- Trainer is almost always also Coach so he explains thinks based on his experience
- Each trainer has "his own flavor" of Agile development which fully corresponds with opening up to newer and more effective methods
- If more your colleagues attend trainings lead by different instructor you can get different experience (based on different flavor) and tweak your own process
- My CSM course was more introduction to Scrum aiming on how to run the process, how to work as a team, how to deal with impediments, how to lead people without power, etc.
- Trainer on CSM course was also interested in other agile practices so he spend some time explaining lean approach and how it can be combined with Scrum
- My CSPO course was more advanced. It was mainly about business perspective and it changed my understanding of Scrum quite heavily. Before that I believed that Scrum is more for developers with some advantage for project management and business but after this course I fully understand that Scrum is mainly about project management and business with some advantage and new techniques for developers.
- It is not pure brainwash. Trainers sometimes (but rarely) admit that Scrum is not for every company and that it has some disadvantages which make very hard using it in some environments (like distributed team).
- The fun is that trainers sometimes disagree with each other - again the flavor. It is good because you can think about their arguments and you know that there is more ways to do that and you can select the best one for you.
- If you are lucky you can attend training lead by Jeff Sutherland (one of Scrum creators) or Mike Cohn
What I don't like about these courses / certifications is commerce. All certifications are only for two years and you have to pay fee if you want extend the certificate. This is the most visible on Certified Scrum Professional offered by Scrum alliance. To get this certification you don't have to attend any training. You need proven 1 year experience with Scrum, write a case study about a project you did using Scrum and pay $250 per two years.
I believe that these two trainings + information from trainings attended by my colleagues + Mike Cohn's books about Scrum, Agile and User stories gave me a great starting point. I'm developer and I would like to attend Developer course.
There are also another Scrum trainings (and certifications) offered by scrum.org but I don't have any experience with them. Still I expect high quality because the founder of the scrum.org is Ken Schwaber (one of Scrum creators).