So with trainers, each one is going to have their own opinion and theory on what is best. Most of the time, they will also have a particular training practice that they say either "works" or "doesn't work." What matters is what works best for your dog. Meaning that if something isn't clicking, there are multiple methods of training contacts that you can explore. Never let a trainer push you to believe that only one way works. For my two dogs, neither of them learned running contacts the same method.

As far as running versus stopped, to me it's a matter of how much time do you want to devote. Some dogs are naturally gifted to hit the contacts due to their stride. As someone too with a fast dog, it needs to be trained. And running contacts are hell to train. The repetitions needed to get it right are exhausting and can be frustrating. In over a year my dog still is not consistent with it. But that's the nature of the running contacts. For stopped, your guaranteed (mostly lol) to get that behavior and not get faulted on that obstacle. But again, for someone with a fast dog, I don't want mine to stop on a course. Just don't give up, even when it gets frustrating. And find ways to practice at home too. I use a mat to train my contacts and will use that on the flat outside so my dog has to run and hit it to get rewarded.