I love the solid sole - you can wear them to run tot he mail box or the drive through. We travelled with them for about an hours journey on country roads and all was perfectly stable. Well every other night. Doing some quick math on the total volume this unit takes in your cabinet vs. USEWhen I put these on, and in just walking around the house they were super comfortable, and in taking the dog for a walk they were perfect no matter the terrain, on the road or in the park. The red ones are more silent. I havent been keeping up on reviews with my purchases, but as soon as I put these slippers on and took a few steps I just had the urge to leave one. It is sturdy and works well even when fully loaded. With that they have been perfect! I usually dont like buying wireless and/or ANC headphones as the sound quality takes a hit but did it to prepare for the inevitable when phones dont have a 3.