To start, NO ONE here likes underground fencing, so you won't get much support here for those. I myself, have underground fencing, and I love it. Sahara, my B will not jump the fence, yes she tried at first but now she does not at all. Once your dog knows where the boundaries are it will not go to near, there is a warning before the shock, the collar will beep twice to let the dog know to back off. Sahara takes off when the beeping starts, she has learned. Yes, I hated it when I would see her try it, but she doesn't anymore. I was at my neighbors last week talking in their yard, Sahara was standing in my driveway whinning for me, she did not jump the fence. Of course she was rewarded for that. Lots of hugs and kisses for being such a good girl. Sahara is home with my hubby until he goes to work at 3:00pm, I work in the mornings, so she is usually sleeping when I come home at 5:00pm. If I didn't have the fencing she would have been hit by a car by now. She loves to chase cars and will just shy of the fencing, the car comes by and Sahara is off chasing the length of my yard. When I run errands I do not worry about her being in the yard, I don't have other animals in my yard, it is against the law here to let an animal run free. I live on a busy street, so yes I like underground fencing, it has saved my Sahara's life many times. That's my story and I'm sticking to it. haha!!!!:D