electronic fences

Question
Just wondering your opinion on underground electronic fences for our dog, Harley, a 10 yr old Springer Spaniel who's developed a habit of wandering off our 1/2 acre lot in suburban Washington, DC.  What brand/make is the best value, do they really work (Harley's very stubborn!), are they hard to install, etc.?  Appreciate any advice you can give.  Thanks.  Mark

Answer
I do not have any personal experience with electric fences.  Most of my clients who do have electric fences have had them professionally installed and are quite happy with them.   However at 10 yrs of age, I am guessing that his quote "habit" of wandering off may be partially due to Cognitive Dysfunction and in fact he may FORGET his boundaries due to age-related brain changes.