Out of curiosity, Torq, did you decide to get something else (and if so, what) or wait to see what will be released in the near future?
I've looked at everything I can think of.
The Pioneer version of the Onkyo will have, I expect, the same software issues as the DPX1 (love to be wrong).
The Calyx-M nails the storage side of things, but has no digital output.
The Lootoo PAW Gold fails on both the navigation and the lack of a digital output.
The FiiO X5ii can mount the storage I need, but completely falls apart if you use it with a large number of files.
The FiiO X7 can't handle the storage and is Android based (which I'm avoiding in an audio player for now).
The FiiO T3 is a good ways off, and I'm not betting on it until they ship a unit and the spec isn't subject to getting nobbled.
The iBasso DX200 is tempting, but it seems that's going down the Android path again.
The only other players I can think of, that can get close on the storage are the AK 240 and 380. They only have one slot, but the 256 GB they have on board brings them up to parity with the AK120 I use now ... they'll just fall behind the moment bigger microSD cards ever show up. Also, I don't care for the signature or aesthetics of the AK240 at all. And even at $3500 the AK380 isn't great with my headphones anyway (no synergy - sucks the life out of the music), so I'd have to change IEMs there. But, if the card-indexing on the AK380 is fast enough I could do that in the short term.
ALL of those would require that I continue to use my phone for streaming TIDAL when on the go. And to get the sort of quality I want that means taking the Mojo everywhere, which I'd rather not do.
So at the moment, I'm a bit stuck as I can't think of any other players that can mount dual cards, has a solid enough DAC/amp, can drive a digital output properly, will run my Bluetooth headphones when I want to use those, decent battery life, a fast and responsive metadata-driven UX, and ideally can do streaming for TIDAL ... all without being compromised by the vagaries of the current Android audio stack.
To get what I want I'll probably have to build it myself - which is a path I've considered before and is something I have the ability to do, both on the software and hardware side of things. I'd just rather not do that if possible. Hopefully Onkyo fix the issues I found and I can just buy another DPX1 before it comes to that though!
Until then, I'll continue to use my AK120 ... which is glacially slow with with my library, has horrible battery life, and does not show me SE846 in anything like their best light. It does work a treat with the Mojo though ... if you can tolerate the UI slowness and 25-minute index times.