NGK Iridium Spark Plugs

My vehicle was not performing great so I took my vehicle to the garage. They recommended that I replace the spark plugs. Here is what my spark plugs looked like after removing them from the vehicle.

When I went to buy new spark plugs I asked 5 or 6 places which they recommend and they all said the NGK Iridium spark plugs are the best. According to the box they claim to use less fuel, smoother idle, and have a longer life. Only time will tell how great they are, but immediately after installing them into my vehicle it does seem to idle smoother and there are no issues with starting the vehicle.