I had a smoother idle. Your not gonna have a seat of the pants difference from any plug. I bought it because they last and have a little better spark they work very well in my Prelude, definatly more top end performance. They are suppose to be good in a car for 100,000 miles. The less you put your plug in and out the better. That's my opinion, less room for problems. I have found aluminum heads to be somewhat sensitive.
I dont know how much you guys are paying for the regular NGK CR8E plug , but I can get them for $1.95 Canadian . A local shop is going out of business , so they are selling off all their stock CHEAP!!!