 Have owned two of these cars. First one was a 3.8L, after a few months was disappointed with the power and shifting . A little to herky jerky for my taste. Traded in on a 4.6L and upgraded two years. Now I have the car I expected and desired. No comparison between engines. 4.6 was far and away superior for my taste.  I will be upgrading soon and will go for the 5.0 just because of the smoothness and overall "feel" of the power. I accept a couple miles per gallon downside, but worth it to me.