professorpaul wrote:
...
The only problem that I've had is knowing that they have been "hit," as
many of them are a "one shot" thing, and must be replace (varistor
type), if a real nasty surge hits them.

I have such devices, in the form of outlet strips, on both computers in
the house.

Any protector that was one shot protection was grossly undersized -
ineffective. When it vaporizes, then it promotes more sales to the
naive. Effective protectors do their job without vaporizing; human
never knows when it is working. But effective protectors are not
promoted by the naive.

Active component in a protector is the MOV. A datasheet from an MOV
manufacturer provides a ballpark idea how many times a properly sized
protector should work - without failing:
The change in Vb shall be measured after the impulse
listed below is applied 10,000 times continuously with
the interval of ten seconds at room temperature.

Does that sound like a one shot protector device? Of course not.
Ineffective protectors are also grossly undersize to be promoted by the
naive. Smoke rather than facts promote ineffetive plug-in protectors.

Effective 'whole house' protectors are manufactured by names
recognized as responsible: Square D, Cutler-Hammer, Leviton,
Intermatic, Square D, and GE. They are sold in Home Depot, Lowes, and
electrical supply houses. They are not sold in Radio Shack, Sears, and
grocery stores. Essential for any effective protector is earthing. A
protector is not protection. Protection is what the protector connects
'less than 10 feet' to: earthing.

Meanwhile, let's look at what some grossly undersized plug-in
protectors have done:
http://www.hanford.gov/rl/?page=556&parent=554
http://www.cob.org/fire/safety/surge.htm
http://www.ddxg.net/old/surge_protectors.htm
http://www.westwhitelandfire.com/Art...Protectors.pdf
http://www.rbs2.com/fire.htm

Think about it. Would you put a protector in dust balls behind a
table or atop a desk of papers? There are overhyped, so called 'one
shot' protectors. Properly earthed and sufficiently sized 'whole
house' protectors are available. And then we have this fact
demonstrated in commercial broadcasting stations and telephone
switching centers everywhere in the world. The protector is nothing
more than a connection to protection. That protection is a good earth
ground. An effective protector is only as effective as its earth
ground which is why effective protectors have a dedicated earthing
wire.