They do run a little tight but not to the point where theyre uncomfortable. So, I ended up getting the 9M/11W and they are still too short while being weirdly wide. I tried 3 separate replacements: Pantronics Voyager Legend, Motorola Hint and the Jabra Stealth. The foot bed is slippery, unbreathable vinyl/plastic and quite hard. The remote paired with my Note 9 quickly and easily, spent the day playing with this, and all worked fine. I cannot add anything to what others have said, so I will take a different approach. The Bass is alot more punchy and not boomy or distorted. The connectivity is really poor even if the phone is just right next to it. it is sewn in to the shoe. Was nervous about new design for these keen kid shoes but they are great and my 8 year old loves them!