The increase in accidents nationwide due to texting while driving is a well known fact. I work at a University, and I've actually witnessed one accident recently and hear about friends and colleagues getting rear ended by texters. It is even indirectly affecting insurance rates (no one admits to doing it!). It is really bad for teenagers, with deaths, every day. When I hear my text alert, I wait for a red light, or ignore it until I am at my destination.
However, I use bluetooth as seemlessly as having a conversation with a passenger. Steering wheel controls are instantly accessible, and my fingers know where they are now. Answering calls, and making calls is not distracting at all for me. I am used to it. Used properly, bluetooth saves lives because you do not have to take your eyes off the road any longer than it takes to check your speed (look at the speedometer). You don't have to find/touch the phone at all.
I am an extremely actively defensive driver (especially after getting nailed last November!). I can actively keep track of drivers around me while using bluetooth. I pause my conversation if any drivers get too close or don't seem to see be yielding. No problem. I do it all the time.
In fact, having two or more children in the car is way MORE distracting than making/answering a call using bluetooth! It is fantastic.
Nav, on the other hand, takes MUCH more attention to follow. Staring at your radio screen is dangerous. It takes your eyes off the road, and breaks your attention to the road much more than children!
I can change stations using the steering wheel controls, too. Much safer than reaching for the radio.