Positive! They use an electronic collar in a motivational sense, are gentle, upbeat trainers who engage the dog's interests with enthusiasm in their voice and movements, and really make a dog happy and curious to work with the handler. NICE program. Dogs trained in this method really are relaxed, upbeat, eager workers! No yanking on their necks, no harsh words, just a very low, gentle tap feeling from the e-collar. Regardless of how I felt about e-collars before, seeing a young dog introduced to this method was amazing.. dog is relaxed with no more leash, less stress of being pulled about.. no more "opposition reflex." I like seeing a dog happy and want to work.
I'm not sure if we're talking about the same "Sit means Sit" training program, but the one I'm familiar with is a franchise, which means that each training facility is only as good as the trainers who work there.
Our local Sit means Sit trainers had a demo at a dog event here recently and I can honestly say that the way they were using the e-collar left me less than impressed, and I would not recommend them (the local franchise) to the average Joe looking to get into obedience with their dogs.
I'm sure experience varies with other Sit means Sit locations. I have to also add, I've seen some Sit means Sit training videos on YouTube that just made me cringe. Some were like Patti said, very positive and leaving the dog wanting to work. Others ... not so much.
That's too bad, I like the E collar and use it the same way you would a prong collar, new skills I teach with positive re enforcement. I seen E collar used for dumbbell and did not care for it. I got Erika to retrieve the dumbbell using it like a toy and play.
You would want to discuss with whatever trainer you decide upon. The feelings range from one extreme to another. There are trainers who wouldn't use a prong and others who insist upon it. And then there are those who will try various collars and ideas to find what would work best for you and your dog.
Here is a link from the leerburg site on how to fit a prong collar.
I use a prong with Kayla in certain classes and situations. I also use a martingale or a flat collar in agility or when we are out on off leash walks. I use a choke/flat when she is in various obedience trials, though I've cut down drastically on the use of a choke collar - AKC events don't allow use of prongs on the trial grounds at all.
If you are starting with a new puppy, I would recommend that you start with a flat collar in your training. You may discover that you won't need to go to a prong at all!
The demo I saw had the instructor doing obedience with his dog. Whe he had to tell his dog to sit 4-5 times, that was it for me. Also, what do the dogs do when the e collars come off? The program is expensive too.