Wow, so wierd I just went here to make a post about invisable fences to see what everyone thought about them! So I guess I'll just post here
My neighborhood doesnt allow fences so most of the neighbors use the invisable fence. I use it with my three dogs and it works great. My aussie doesnt wear his collar anymore, he is trained the best for it and knows his boundaries. If he gets close to a boundary (only happens if his ball rolls across or he wants in the lake) we just say get back and he will back up. He asks permission to jump in the lake, and will not go in until we say ok, go. He has been trained on it for about 5 years. Preston is very good about it to, never goes near his boundaries. We do put his collar on him to be safe, he's a little guy and gets very excited about UPS trucks, but has never crossed his line for one. He's been tained on it for 7 years. Duke is the most difficult, he took a lot longer to train and it was much more difficult for him to understand that the flags were his barrier. Once he learned it he was fine until this year(3 years later). He has started running through it when we are across his line. Which has started since I went to college and my family has let him get away with it. I am starting his training over now, putting the flags back up.
Now my first neighbors that his this had 5 dogs (2 beagles, 1 aussie/GSD, 1 border collie, and 1 terrier mix) who spent the time needed training and their dogs stayed in the yard very well. The beagles did take more time to train, those noses get them in trouble. I have another neighbor with a boxer and cocker spaniel that also spent the time to train their dogs properly and it works very well for them. The boxer was the hardest to train and would run through it the first summer, but does well now. Then I have the neighbors who did not train their dogs. One of the families has 2 very very large labs that run through like its nothing. They didnt spend much time training and just let them get away with it. Another neighbor has a golden and boston terrier. These dogs do not stay in the yard, and actually I dont no how much time they spent training. The golden stayed in the yard until they got the boston who runs through it and has gotten to the highway(3 miles away) and been hit. the other neighbor that didnt train also has a lab(averaged size though) and she actually stays in the fence, but had very little training. the last neighbor that has it has a lab and golden that they did train for it. However they keep changing it, they put in a new one to make their yard space smaller and smaller. Those poor dogs are so confused they dont no where they can go. The lab freaks out if you try and take him outside of the yard for fear of getting shocked.
IMO these fences are fine if you live in an area that isnt busy (county). They take a lot of time to do the proper training for them to work. It can work for hounds but they are going to be more difficult to train. From what I've seen different breeds do better with them (when trained). I feel like labs, for example, are very difficult to train on these, they dont seem to care about the shock(which honestly isnt a bad shock, I've accidently had ahold of the collar and walked across the line several times. I love that our dogs have 2.5 acres of yard to run around in, that they wouldnt have without the invisable fence, but I have heard of so many dogs that run through them and will get hit by a car. this is something that you must continually work with your dog on, and the dogs should be watched while in the yard.