Features on the Supertooth 3 also include an automatic vibration sensor reconnection. So if you open and close the door to get in the car, it'll sense the vibrations and automatically find your handset to reconnect. Other features include voice command and dialing if your phone supports it.
It also has full duplex sound and noise suppression/echo cancellation technologies. Our tests definitely support this--we could hear our callers just fine, and they could hear us very well, too. They did report some echo and static at times, but it wasn't a deterrent to conversation. Volume was definitely loud enough. We're a bit soft-spoken, so we sometimes found we had to speak up quite a bit, even when the microphone was directed toward us, but that is common with most speakerphones.
The Supertooth 3 comes with an in-car charger plus an AC adapter. It has a rated talk time of 15 hours and a standby time of 33.3 days.