I'm wondering what specs. to look for, or if they're all pretty much the same. Some retailer's descriptions are pretty vague, and draw more attention to the pretty lights and meters, while never mentioning the unit's actual capabilities. The only feature(s) I must have: an unswitched plug on the front. And (I guess) a front mounted circuit breaker. I assume they all have EMI/RFI filtration (One in particular advertises 20 dB reduction). Most units have 15 amp capacity (is this "enough"?), 20 for some. Then there's "three way spike protection" (sounds a little kinky). Which, if any, of these things are important? Thanks in advance for any opinions.