Upgrade over the UP4, adding a dedicated play/pause button, a screen, a 4.4mm output, and a leather case. Drives all of my headphones with ease, has great battery life, and fits easily in the pocket. I love the tactile volume wheel on the UP5 over the volume rocker on the Qudelix 5K. Volume wheel on my UP4 felt a little tighter but not a big deal. The app isn't great compared to the Q5K, I uninstalled it. Overall love it, will be used more than my Q5K, and replaced my UP4.