My neighbour had an electric fence to train their Schnauzer Victoria. Once she was trained to know her boundaries it was disconnected. It was fun to watch Victoria tearing down their driveway barking like crazy and coming to a sudden halt at the end knowing that was as far as she could go and this was years after the "fence" was removed.
I'm not sure I would use one in a situation were dogs were allowed out to run free all day because I would think there is no guarantee other dogs or animals wouldn't get in or the dogs figure out they could get out but then I wouldn't let a dog run free, unsupervised all day anyway.