[lcaillo]

The reason that there are mixed signals is that the actual energy that needs to be dissipated, the time that it takes to dissipate, the paths that the current takes, and therefor the actual current that is experienced at any point in a system is so variable that it is hard to generalize. Every lightning strike affects not only the immediate property upon which it falls, but dozens nearby. Any one of many homes might see a 50kA surge or anything down to zero. Because grounding effectiveness varies so much the way in which the energy is dissipated is very much unpredictable.

As with most issues in the field of consumer electronics, one must combine reasonable analysis, theory, and field experience to come to conclusions that have the highest probability of being correct. Testing and theory tell us that MOVs can degrade with repeated operation. Field experience does not demonstrate large numbers of failures of MOVs, nor of devices connected to quality surge suppressors that use them.