Well....I got this thing today, it is so far (knock on wood) a complete godsend!!!!!!!
We had him trained to hit the door before it would open, but he never did it unless we had his leash on him and we were taking him out because he looked like he had to go.
I put it up, 30 mins later "ring-a-ding-ding" I hear the little bells....I run out to the back door with his leash, totally forgot my coat and shoes, ran him outside as fast as I could and the little dear had a pee right away!
Feet soaked, getting rained on, it didn't matter I couldn't have been prouder!
He's rang it three times since, and each time we went out and he did business right away. I think it's clicking in. Each time he rings it, whether it's just to be nosey or chew at it a tad we will take him out so he knows that sound means the door will open and he'll get outside. So far each time he's produced when he's rang it.
God only knows how many times he's probably gone to the door in the past weeks, and we just didn't notice!
Now he has a way to alert us, I completely recommend this to anybody thinking about it.
(Gonna knock on wood one more time just incase)