I have been using the pet safe brand for about  6-8 years now on my Husky (loves to run straightlines for 30 miles.....).  We have gone through one shock collar but other than that, they are great.  You do have to keep an eye on the battery if your dog is smart (the collar has a light that blinks when the battery is getting low) but mine will last several months.   I can even let mine be dead for several weeks until I catch my Husky testing the limits, then it's time to replace it.  It's funny to watch him get excited for a walk/run when I take the collar off, but he still has to be convinced that it's safe to cross the line, but once he gets across--it's 100 mph until he is totally exhausted.