I had LOF, air and fuel filter replaced when I bought my 06.
Engine idled smoothly, but seemed a little sluggish.
Its a 3.0 L with 70,000 km (43,000 miles).

On a hunch I had the complete injection system including MAF & IAC cleaned and then the plugs replaced.
Ford Motorcraft plugs.

Engine seems like a different beast if you can call a 3.0 a beast.
Revs up much quicker and pulls smoother.

Definately worth the money to do this preventative maintenance.

I'm gonna check my mileage now to compare.

I just did my 4.0 at 65k miles all new plugs and whatnot.

Made a HUGE difference man. It pays to stay on top of these things for sure