I saw those a long time ago, but was quite skeptical at how it worked considering the wiring diagram; One uses two circuits
downstream of the main lines - on 12ga wires?? But for $175 it might be worth finding out.
There are a few different ways whole house surge protectors can be installed but it's effectiveness is more or less the same. The destructive surge would seek the easiest and shortest path to ground (the whole house protector) which will harmlessly dissipate the surge outside in earth.
