OK, so no need to teach my Husky to bite the postman... the DAC was delivered.
Did some quick tests.
My IEMs are DITA Project M using the 3.5mm connector to start.
I use Spotify for my music source.
Definitely improves the quality of the sound.
Music is crisper / cleaner. I heard things that I didn't know were there.
I tried a different USB-C cable. One that I use w my external hard drives that are rated for 10Gb/s data xfer.
Honestly sounded slightly better... a little cleaner. I mean if you were listening casually, you'd miss it. But if you were paying attention you'd hear it.
My guess is that its slightly better cable and more power is going to the dac. Better shielding.
The only negative... for casual listening... when out and about... the Apple dongle is easier w the iPhone. When carrying the iPhone and dac, its a bit more of a pain when you want to change volume or skip a song. But that's going to be true of any dongle that's not just a cord.
That said... definitely worth it and will use it when I want to listen to music.
If I'm just going out and about... have to think about it.
Sometimes its just easier to use my M&D MW08s (Bluetooth IEMs)