used w/ Pioneer AVH1440 NEX radio & Android phone. The only noticeable difference is the main side button is dished in slightly on the XR700s vs the raised button on the XR500s. When I put on a thicker sock the width feels a little wide and toe room about 1?. I mean I feel like I have a normal width foot, and I typically wear a 9. Upon opening the box, the first thing I noticed was the compact design. I played Call of Duty cold war for hours with it, battery life holds good. Wish they would have worked, but I returned them. These shoes are just wicked comfortable, and my feet felt very stable in them (I work in a high security facility, so stability is important). Great for on the go; however, it does run a little small. He also mentioned (spenco foot support) which i got from academy sports.