.When I first got these earbuds there was a bit of a learning curve to connect with my iPhone 5s. I also connect to a Bose Sound Link mini, a JBL Flip and a Kinovo bluetooth receiver in my car (all of which are excellent!).When I first got the GOs I would always have to activate bluetooth in the iPhone to connect tp the buds. Then I re-read the instructions and I realized that I was holding the activate button on the GOs too long so they would always go into pairing mode. Now I can go from any bluetooth device to the other without pairing.The sound is excellent for earbuds, the ear fit is good with the medium sized inserts and the buttons work well with my iPhone. 

Question: How was the fit?
Answer: curve