I am looking to separate the "music" role away from my phone while traveling. Here is my use case, wish list and budget:
I mainly travel with my Kumitate Lab KL-Kanon Custom IEMs, but also have a few more sets of customs, as well as ASG 2.5. I currently use android with an OTG connected Fiio E17K. The main reason I bought the E17K was because of the super granular bass settings. -10 to +10 in increments of 2 adjustments for bass and treble.
I like the idea of the android based DAPs, but it must have hardware buttons if it's droid based, so I can adjust tracks without looking.
Balanced Headphone Output
Standard Charging and Connectivity Cables (Sony, you're out. NO proprietary cables!)
Physical Buttons for track advance/pause/vol/etc..
Granular EQ (more than just bass boost off/1/2), if Droid, OTG would be nice. I might use this DAP with a Mojo or my E17K in the future.
Budget: Let's say $650USD, approximately. I'm willing to spend 2K on CIEMs because they will last 10+ years, but a piece of technology.... not so much. Don't see the point in blowing 2K on A&K, although they are built very nicely. $1000 hard limit.
I'm currently considering the DP-X1A (About 600USD because I live in Japan) or XDP-300R.