Ok, you made me look at their site...
The Neon SRT4 they put on a dyno gained 3 HP.
http://www.sparkplugs.com/sparkplug4...-+SRT-4&mfid=0 That's something, but not really worth $100 to me. The SRT4 also has almost 200 HP, which may put the gain on a 145 HP Ecotec closer to 2 HP. I may buy a set before I dyno my car and see what they actually add, if I do, I'll let you know what happens.
Another thing to consider, the iridium plugs I have now I paid $12 each and they last 100k miles. That makes the Pulstars about 4x more expensive per mile since they only last 50k miles. I've done some tune-ups on Ecotecs with 130k miles on them and the plugs still had the correct gap, so although I'm not recommending it, I'm sure they could go longer than 100k.
Since an image on the Pulstar site reminded me of this, here's another way to improve a spark plug, but it's such a PITA I haven't tried it even though I have a metal lathe and could do it a lot easier than most people. This is another one that requires copper plugs. You bend the outer electrode straight enough that you can get a drill bit the diameter of the center electrode to the center electrode to cut a "dish" into it. Bend the outer electrode back and gap it, then drill a 1/16" hole in the outter electode centered over the center electrode. This is supposed to send a "pencil torch" like flame past the outter electrode and increase the speed of the flame front, burning more fuel quicker. If you decide to try this, check your plugs at 15k miles and then every 5k miles after that until you know how far thay can go. As the outer electrode wears, the thin part around the hole wears out first and can completely wear away which makes the tip fall off into the cylinder.