Excellent summary of collar options! We started out with the flat buckle collar, but were suffering from too much pulling and refusal to heal/sit on command. A few weeks into obedience class, we switched Ginger to the pinch collar and the change in her 'tude was quick. My understanding is that it is meant to mimic mother nature -- when pup gets out of line, mama grabs pup by the gruff of the neck. The pinch mimics that discipline and Ginger seems to get the message.
We plan to combine her training with both the pinch and the flat collar as we don't want her thinking she only has to obey our commands when wearing the pinch. Our trainer advises that it is our voice and actions that should be commanding the dog, not the collar/leash. As she is only a pup, when Ginger gets excited, our commands don't hold too much weight!

So, I thank the doggy gods for the pinch collar!