They do have a much more powerful spark because they basically put a capacitor inside the spark plug to create a bigger spark. You guys ever heard of Nology hotwires? They have the same concept, a capacitor built into the wire with a ground strap hanging out to give the spark plug a much stronger spark. Its the same thing but inside the plug instead of the wire.
I have personally seen a demonstration of the difference between a normal msd spark plug wire on an msd system, and a nology hot wire and the difference is HUGE. It makes a BRIGHT LOUD pop for each spark. We put a sheet of paper in between the spark on both, and the regular msd system did nothing, the spark went right through it. But the paper going through the nology plugs caught on fire immediately.
Anyways, I've read a few articles on these spark plugs and they give like a 2% increase in power and torque production over the top standard type of plug. Its a great idea I think, I dont know about how long they will last in real world use though. Plus its a bit expensive for a set of plugs.
Personally I think they would actually work, and they seem like theyre on a different level than tb spacers, magnets, tornados, etc.