I should start that I can't comment on how well the Roav F0 handles phone calls because I haven't taken a call on it yet. That being said, I've been using it for about a week now and I have not been disappointed. It is super simple to use--basically just plug it in, find a FM frequency not in use (out of the box, the F0 unit will be tuned to 107.1 and that worked for me), make sure the bluetooth on your phone is on, and once you've connected the two devices, you're good to go. The bluetooth connection between my phone and the F0 is strong, no matter where in my truck I've placed my phone (in a dashboard holder or on the passenger seat). The sound is clean, as though I'm listening to a CD or the radio. I was afraid I'd get some interference from radio stations and other frequencies, but there hasn't been any of that, and I've driven all over San Diego--past Navy bases and the airport, through residential and commercial areas, you name it.
TL;DR: for anyone with an older vehicle, the Roav F0 SmartCharge is great for anyone tired of listen to the radio and would rather stream music/podcasts from their phone.