Pros:Sounds amazingPerforms perfectlyNice designComfortableCons:A little too bigSwitch gets pressed unintentionallyI got these for the sole reason for taking it to the gym. I do not like cords slowing me down or getting snagged on gym equipment and this headset is perfect for the job.It syncs with most phones or audio equipment with A2DP compatibility. My Sony W810i did not have it so I switched to a RAZR V3xx so that I can have the ability to play music and phone functionality. It plays music in stereo and the sound is amazing. It also pauses the music when I get an incoming call while Im doing my workout sets. Press a button and you can toggle between call and music. The left ear unit works as a cel phone bluetooth headset by itself with the volume controls (and flashing blue light) when paired with a phone. When used as a music headset, it enables both earpieces to be activated, together with the rew and ff controls on the right ear.The unit has it share of some flaws too. First, it's big. It sticks out a little too much from your ear due to the padding and the sheer size of the unit (Hello, Princess Leia!). If it were smaller, i would had given it 5 Stars. People complain about the flashing blue light....you can turn it off if desired so it's a non-issue. The neckband is comfortable though a little flimsy. It wobbles due to the weight of the ear units, I would had preferred if it were sturdier-looking. The control buttons are huge too, it takes up 3/4 of each of the earpieces. They can be accidentally pushed in your bag or any confined space and there isnt a way to lock the buttons.Overall it's a good product - range is good, and the sound is amazing. The mic also is sensitive and perfect for taking calls. My friends say that they cannot tell Im using a heaset when Im taking to them. One word of caution though, some States do not allow both ears to be covered while driving so it might not totally replace those dorky one-ear celphone bluetooths you might have while you are driving.