My cert is through ACE. It was the most generic, white bread class you could get. It was all really basic stuff about general medical/legal issues, A&P, and basic exercises. Given the fact that I am a firefighter/paramedic, it was more or less a review of things I already knew.
I have learned FAR more by working out with others, reading books and doing searches on the internet, than I did from the class. My certification protects my employer, but it has done nothing to make me a more effective trainer.
That being said, the exam was pretty easy and if I choose to renew, it should be simple. That is a good thing.
I cannot speak to other certifications, or even even other ACE courses (mine was one of many they offer). All I can say is that from what I have seen, a cert is a cert and there is no need to get too worried about who issues it.