I recently swapped to an iPhone with the iPhone cradle (previously had SAP and Nokia) and am very pleased with sound quality and reception.

Just a couple of observations;

If I get into my car within range of a WiFi hotspot and the iPhone is connected to the hotspot (which it does with wonderful ease!) the phone will not establish connection with the car. Even when I have driven out of range of the Wifi connection. Bluetooth connection to the car can only be made if I hold down the button on the cradle.

Secondly, there is a significant time lag (3-4 sec) between pressing the call connect or disconnect buttons on the steeringwheel and the system responding. This was instant with the SAP module. Is this normal? Presumably it's the bluetooth connection slowing things down?