I have a desk job and had the shoes on for only 8 hours and had a blister the size of a quarter. One minor quibble is that it will shuffle songs, but it wont shuffle albums, a feature that I loved on my old iPod Classic. For sizing, if you have two people working out at the same with an active class like F45, I think the 10x6 is the smallest Id go. This is perfect for us! These Amazon cables - the connector end has become worn / degraded from just a few connect / disconnect cycles, to where the cable is now loose in the port. But I learned to push my foot towards the front so that my arch would rest completely in the bottom of the shoe and not slide around. The first thing I noticed when opening it is the packaging, a very small box that did not look like a quality item at all. How much it cost for so little enjoyment. So what is it like to use the Utaxo True Wireless earbuds?Build QualityLike most true wireless earbuds, the Utaxo True Wireless earbuds are made entirely of plastic, which makes them lightweight and easy to wear. No breaking in needed.