We paired the Jabra SP700 with the Apple iPhone 3G and the LG Incite. We were quite impressed with the call quality; callers could hardly hear background noise and there was little-to-no echo from our end. They could still pick up road noise, but it wasn't that bad. That said, we have heard reports that road noise is a bigger issue in larger vehicles, so test it first if you have a van or a truck. We heard our callers loud and clear. We did get quite a bit of static occasionally, but it wasn't a deterrent.
Since the iPhone 3G doesn't have stereo Bluetooth, we tested the streaming music with the LG Incite. The SP700 immediately started to stream music from the phone, without any prompts. The audio quality is on the tinny side of course, but like the call quality, it has plenty of volume.
To transmit music from the SP700 to your car's stereo, simply press the FM button on the speakerphone, and tune in to the announced FM frequency. If you wish to change the FM band, press FM again and then press the Volume up button until you hear "Scanning". You can scan until you find a satisfactory FM frequency. You can use the FM transmitter for both phone calls and streaming audio. We tested this in an older Honda Civic, and the audio quality improved significantly. That said, because we live in a big city like San Francisco, it's hard to find a non-congested FM frequency; you'll likely have better luck in a less congested area. The FM transmitter turns off automatically when not in use.
The Jabra SP700 comes with a USB charger as well as an in-car charger. It has a rated talk time of 14 hours and a rated standby time of 10.6 days.