The wheels bent and cracked like eggs under the weight. And each song has such a wonderful message! So I was looking for something with a better design; up was hesitant with these but decided to for the good deal plus the case and arm band. Cons (to be honest, difficult to come up with these which is a great thing)-The volume button on the right side is sensitive. The hinge that holds the lid to the rest of the body is pretty thin so I have no idea how long that will stay attached. I have only used them a few times so far, but they are well built and should maintain their quality for quite some time. I hope they last for a good while bc ever since I had foot surgery a few years back I have such a hard time with comfort. Therefore, once the racks were installed, they would slide back n forth and the only way to secure them, would be to wedge something in the track. Is it comfortable?Judging 650BTNC is subjective, as it requires the process of comparing with other wireless headphones within the same price point. This controller has multiple buttons on it, and one of them controls the THX Spatial Audio.