I installed one and it has worked well. For years now. But they are no perfect. Most important is your type and size of dog. My dog is an Austrailian shepard (kind of nervous) so it works well cause she doesn't like the shock. But she has run through it at times. Some dogs will just run through it. Also, important is to train the dog young (but not too young) so that they develop a fear of the wire. Now my dog won't even go through the wire if it stops working for days (she's developed the habit. Maintenance is a burden with the system. The collar receivers don't last forever (I've been through 3) and you have to change batteries, and worst of all, the wire is only about 3-inches deep, and I've cut it (aerating the lawn [rolleyes]. It's not too hard to install. I had to cross my asphalt driveway, so used a rented diamond saw to put a groove across it. then layed the wire in the groove and cemented it with asphalt sealer. All in all it's been cheaper than a fence and has worked.
If your dog is jumping fences, it may already be too old for this system (but maybe not). It works better when they're trained young. Call [url]www.radiofence.com[/url] for advice. They are experts, had the best prices (that I found) and the have been very good to deal with.