The ping watchdog is great for units that are difficult to physically access. If they lose their network connection, they reboot. Maybe that will help them.
When changing configurations, you can "activate" without saving your changes. That way, if you mess your connection up and cut off your ability the log in to the unit, the ping watchdog has a chance to reboot due to loss of connectivity. Since you did not "save" the changes, the unit will revert to its prior configuration upon reboot. Once you get the unit into a stable configuration, you can finally "save" the changes.
Remember that if you have the ping watchdog enabled on a unit sitting on the bench in your shop, you may find it rebooting all the time.
A special problem arises in networks that have failover behavior through dynamic routing. If a link goes out, the failover may keep your customers' traffic flowing, but the ping watchdog may be blocked by the failed link, leading to regular rebooting. Furthermore, you may find it difficult to use one of the dynamically routed addresses as the target of your ping watchdog. This can be a tricky issue to work out.