There are so many different types of trainers with different philosophies and methods.
I have always said to keep an open mind. I always mix it up. I am not a treat trainer..BUT if nothing else works than I most certainly will resort to it. I find it very sad that trainers stick to one method (their method) and not go outside the box. I find it very informative and also enlightening to take different courses or watch different trainers 'do their thing'. I like to incorporate many different ideas and I would never stick to one method..it does not always work.
It is important for those taking courses to feel comfortable about how their trainer are working with their dogs. If something does not sit right with you..then get another.
For me personally, I will at times resort to a more 'dominent' approach if required. Really, it depends on the dog, the issue you are dealing with and the limitations of the dog.
People however are getting alittle too sensitive with a more direct approach to training. Some dogs require a more hands or they may require a harder lined method.
I do not believe in clicker training for obedience. With that said..if I was failing in all other avenues I certainly would try it.
I my opinion all trainers or those that train have something very valuable to share. All dogs are different and the key to success is finding out what the triggers are (if we are dealing with issues) and then finding a remedy to help the dog overcome.
I say 'mix it up' and don't get stuck with training only one way.