Anyone compare iPhone 4 and the TomTom 1.4 GPS reception quality with and without the car kit? Does the car kit still provide significantly better reception over the iPhone 4 internal GPS and antenna?

I found the car kit provided better GPS reception than the 3G or the 3GS internal receiver.

 

The iPhone 4 GPS chip and antenna are much improved over the 3G/3GS. It's the same GPS chip used in the iPad.

The car kit still seems to be at least on par with the built-in GPS on the iPhone 4, but not far enough ahead for me to consider the cost worth it. I'm actually planning on selling my car kit and swapping out the car kit for a different mount.