It really depends on the dog in question. Some dogs, like huskies or any sight hound will tend to go right through it, being more focussed on the chase or the run than any minor pain. Beagles, too, will be so focussed on following the squirrel trail that they might not even notice it!

Other dogs will do just fine with it. I'd never leave a dog unattended with one - it does not stop humans from crossing the line and stealing or harming the dog, for example. But I know some dogs who do very well with it, and it is helpful for their family, as some of the yard is hilly, and some swampy, and trying to put an actual fence in would be nightmarish!