No, it's not just about Joules. That's the same as saying a PSU is just about watts. I don't remember everything I learned (I'll explain what I mean below), but I know that there are a few other things to consider, such as the clamping voltage. Here's an example of a very high-end surge suppressor:
Don't let the $50,000 lifetime insurance fool you: that's because it's not designed for a home theater system! If the insurance protection is important, then here's one that has protection for up to $500,000 and it's practically the same unit:
Here are the rest of their premium surge suppressors:
Anyway, here's what I meant (as promised): about 4-5 years ago, I wanted a surge suppressor, so I spent a good month doing heavy research on these things. I learned a lot, but I didn't retain the majority of what I learned because it's like the old saying goes, "If you don't use it, then you lose it."
Well, I lost it. However, I still remember learning that there's a LOT more to these things than just their Joule rating. Don't be fooled a unit that promises a high joule rating with a low price because it probably has a low price for a very good reason.
If I remember correctly, I think I began learning by simply Googling "best surge protector". I am looking at one article right now that I think I might have read among MANY (please read more than 5):
Again, I did at least a month's worth of research. So I recommend doing some research of your own in order to avoid getting ripped off.Edited by TwoCables - 8/22/13 at 9:00pm