Can You Recommend a Good High Res Digital Audio Player?

Though not a direct answer to your question, something to consider as you’re thinking about DAPs... in case you are in the market for an android phone...worth checking out the latter videos by John Darko if you haven’t already..https://www.youtube.com/watch?v=bsc8H-ffzLY            https://www.youtube.com/watch?v=Ht45Xbp283U&t=91s               https://www.youtube.com/watch?v=HoDcFzwhlhk          
https://www.youtube.com/watch?v=PzR__lMWS3s           
https://www.youtube.com/watch?v=6r4Sj16zp3I

I just purchased an A&K AK70 new from Amazon -- not a current model but great value at $450 or so. A&K have a broad range of excellent models any of which would meet your needs so look out for a deal at the price that suits you.

The interface is pretty foolproof -- on the DAP it's 100% intuitive and the only nit is needing to use an Android file access app to synch with my Mac which is clunky but works ok -- for some reason the album art doesn't always synch but for me thats not a big deal

Matching them with a great set of IEMs (I use the Campfire Audio Andromedas with the SXC8 cables (costing in total 3x the DAP) is the way to go and provides great performance on the road -- I find myself rediscovering tracks in my digital library I then love to explore back on my main system

Also check out Simaudios Moon Mind 180, seeing a few on the used market now. Software/apps work a treat now, originally a bit clunky but now all the issues have been ironed out. Audio reproduction is sublime supporting all the formats and resolutions etc.. 

NWZX-300 that is the Sony player that I have and it’s definitely portable