I have both players, and they are very different players. QP1R is to me the king of SQ out of the players I tried right now, I even prefer it to AK380. But its UI is dated and getting to essential functionalities can be a chore.
DP-X1 is android with touch control, things like browsing through music collection, applying EQ (I really like the Featured EQ collection btw), searching for songs are very intuitive; plus you have a lot of customization in the forms of digital filters and clock control. I put tidal and other service as a nice bonus feature, it's convenient to quickly search for a song not in the sd-card once a while and see how it sounds with the player. Granted that the SQ out of balanced is not as good as the QP1R, but I say it comes pretty close to my ears. I wouldn't ever complain about it.
The battery life of the QP1R so far has been great! The DP-X1 on the other hand, drains fast, charges fast, small battery, what can you do?
So all in all, QP1R is probably worth every single dollar and more as a pure audio playback device that drives IEMs and hungry headphones alike; and the DP-X1 on the other hand is a complete package with lots of bells and whistles, and still manages to sound pretty damn good, balanced cable is much preferred to reach its full potential.
I intent to keep both, I love them both. If you are to choose one, QP1R for SQ, DP-X1 for versatility.
Hope this helps.