I got this as an all-in-one in-ear solution for my band. We are a 4-piece and can run 4 sets of headphones, each with their own mix. It has built-in headphone amps with 4 outs, so I didn't have to worry about building a rack. (yes, we are using long cables instead of wireless, please cashapp us some money)
There are LEDs next to the volume sliders, which show you where your volume was last set on — so when another musician moves the sliders to get the volume right for his mix, you can go back and adjust your mix without an issue.
You can save your mixes to 4 different Scene presets, so you can always save your mix and go back to it if you mess something up.
Also, built-in reverb, so the sound in our ears isn't "dry". The EQ helps shave off any guitar high frequencies that may be too harsh in the earphones.
I wish the EQ was also customizable per headphone out. As it is, each mix can have various volumes and various FX return applied to them, but the EQs of the channels are a global setting, which is a bit of an issue when we are using different models of earphones.
This is marketed as a tool for podcasts and I can absolutely see it working this way. The microSD card slot is awesome for recording our practices, too! Plenty of in and out options, controls feel fluid and responsive, it was a great buy.