Hello,
I ordered the D70 and tested it for a few days, and compared it to my Gustard A20H dac, which also has dual AKM AK4497 chips, but uses dual-mono configuration. Both were used in a fully balanced config, with a Pro-Ject Head Box DS2 headphone amp, with the same AK4497 built-in filter called 'short sharp'.
I really wanted to try out the D70, thinking it could be an upgrade, but it wasn't. There was a little bit of increase in resolution with the D70, with slightly better separation between the instruments, but it definitely lacked general punch, bass was recessed (yet the A20H does not have artificially boosted bass), there was a bit of lack of treble extension and the soundstage sounded a tiny bit narrower. That was a big no for me. I could not enjoy the music as much. I'm not a believer in dac burn-in, so I'm going to send it back for a refund.