If you have equipment worth protecting these are the greatest
These are surge protectors extrodinaire! But are much more.
These also suppress "common mode' noise carried in on the power lines. This is noise between the hot line (120V 60Hz) and ground. Sensitive devices (like copiers/MFPs) and be adversely affected by this noise. el-cheapo surges don't do as good a job at surge protection and do nothing for noise on the power line. Also, if you have a fax, the fax filter really protects the equipment. I've seen these ESP protect the equipment plugged into them when everything else in the building was taken out be a near lighting strike.