I hate invisible fencing for all the reasons mentioned in the article posted by the OP. There is a pair of pugs at a house near mine, that I pass every day on the way home. I think the count of me driving onto the shoulder and jumping out of my car to go drag the pugs out of traffic is at 6 times now. Very friendly little dogs, right on a two-lane, 40mph street that is packed during rush hour. Still, every time I take them back to their house, their owner is horrified that the "fence isn't working!"
I just don't understand it. At least after the fourth return, the owner finally put on tag collars. I told her if she was going to continue to use the invisible fence, she needed to at least have tags on her dogs at all times.