Well I tried out the iPhone 4 with the Garmin Resident Map set and it worked great. The voice turn by turn was right on time and clear as a bell in my Sena BT headset. It even muted my tunes when it wanted to talk to me. The screen is high res enough that I can see the important stuff in spite of the small size. Good enough for what I need it for, when I need it. Just saved myself a butt load of money buying another GPS that speaks A2DP.