I think e-collars are awesome! With that said, you have to first educate the dog as to what the stimulation actually means.
I've seen MANY people, especially those that have been already training their dog with traditional methods, who don't realize this. Then, when they stim the dog, they think the dog already knows what the stim means, but he doesn't, so he doesn't respond the way the owner thinks he should. Think about it, when you teach a dog with traditional methods, he knows what a tug on the collar means. Now, he feels this lite tingling sensation and goes, "What was that?" He doesn't even know he's supposed to do something, let alone know that that thing was, you know what I mean?
So, what do these people do? They raise the stim level thinking it wasn't strong enough. Pretty soon, it HURTS the dog.
But, if you spend the time to teach the dog that the stim is the same as say, a leash tug, then you can use a low level and it really is more humane, in my opinion, than any other standard method that can produce a 99.99% reliable dog. No dog is perfect, which is why I left .001% room for error.
I've been training dogs for more than 25 years now, and I've also seen people that think that an e-collar is a cure-all, or substitute. These types of people end up getting extremely frustrated, and use a high stim level on the dog for everything. The result is what we call a "burned dog", not because of the electrocution or anything, it's just a term. A burned dog will be reliable, for sure, but not in an enthusiatic way. He comes running to you with his head down, instead of bounding to you with joy.
But, do it right, take it slow, like with any other method, and you can train a dog to be reliable with an e-collar much faster than using ONLY standard methods.
Disclaimer: This is ONLY MY opinion and experience. Your mileage may vary. I do not recommend the use of an e-collar without consultation of a professional animal behaviorist. I am not liable for any of your attempts to .... yada, yada.
Now, as Johnny Storm from the Fantastic Four would say, "Flame on!"
I'll get the popcorn, now.