It depends on the quality of the surge suppressor. The important details on a quality device are covered here:

http://electronics.howstuffworks.com/everyday-tech/surge-protector7.htm

Most people don't take the time to understand the ratings for clamping voltage, joules suppression, and response time... and the $9.99 surge suppressor generally isn't much better than a power-strip but people can't understand paying $70 for the quality one.

The best ones usually have some sort of insurance policy-like guarantee against equipment damage, as well. *AND* they need to be replaced periodically because they're taking the hit so your devices won't.