Why would you want to listen to open back headphones namely Grado SR325x on your moble? You realise when you're commuting, everyone can listen to your music and vice versa.
I would have thought, having a fully functional OS such as Android, would be a strength not a weakness and despite having similiarity to a phone, it isn't a phone, you can't make phone calls. I'm not a big fan of SONY DAP's, the quality is good but there always two steps behind with the latest technology and features.
The DAP I'm using, has Android, which is great, I can download all the streaming apps, such as Tidal, Deezer, Spotify and et'al but I can also Tik Tok, how can I function without the funny cat videos. The feature that stands out for me is the Hiby music player, as softwares go, it has a great interface, makes managing your music files a doddle.