Summary: With other devices, I've always had a hard time hearing on them (I don't have a hearing problem). With this device, I never get frustrated that I can't hear the other...
Pros: Light weight, sound quality is perfect, music sound very good and the talk time is six hours which is longer than Jawbone, blue ant, and plantronics. I love the App>
Cons: Not really a con because I get email updates, but when the I Phone has a firmware update the 510 needs to be updated as wel. I guess if you want to use an App you have...