iridium Plugs?

Well its time for a time up again.... Currently have AC Delco Plat in car, wanted to know if anyone has used the new Iridium plugs.
I know on my 3.8, when i tried a different plug(other than AC Delco), the car ran poorly.

Thanks!

Iridium is a waste of money unless you are running a very high-end racing motor. The Delco platinum OE plugs in mine performed flawlessly for 115,000 miles, I finally changed them cuz I couldn't believe they were still firing. They don't even look that bad. Doesn't get any better than that for a street application. Just go OE.