Activity tracking (tracks heart rate, steps taking while running and swimming)
Updates always adds new features.
Noise cancellation works great.
Transparency mode - an amazing feature which lets you listen to music while hearing things around you so if you are riding a bike ir running in a busy street you can still be aware of your surroundings.
Not the best sound quality. The Dash sounds very clear and pure but is not loud. I wish the sound was a little better.
Bluetooth issues while the phone in your pocket (the headphones struggles keeping the connection with the phone if you put the phone in your pocket) this issue got better after the latest update.