Got a couple little Schiits in the mail today. Went with the Modi 2 Uber due to the standalone power supply, and the Magni 2, since my Duet takes care of stereo out to my speakers. Was using Fulla previously.
The Schiit stack, to my ears, does make listening more pleasurable... the noise floor of dirty USB electricity I got on Fulla is gone. At listening levels, Angie is now dead silent when it's meant to be. I haven't actually tried cranking the volume up beyond listening levels because, uh... it's beyond listening levels, so who cares. Sound stage/stereo imaging feels better, though I can't put a finger on one thing I hear more clearly, per se. Similarly, I don't necessarily hear THD or IMD exactly, but I can say that the volume level that feels "too loud" on the Fulla is noticeably lower than the "too loud" threshold on the stack.
Overall, the general experience is more immersive to me, though it's not as clear a difference as the Fulla vs the slightly darker, slightly muddier iPhone 6S Plus, or the significantly darker, bass heavy Apogee Duet. I think the relative darkness issues come down to impedance matching... I tried the Accudio app on the iPhone which did brighten Angie and give it some more clarity, but it also wound up making the highs sound a bit shrill in my limited listening (ALAC Dark Side of The Moon), which they never do otherwise. I could tell right away that the un-EQed Schiit Stack version (streaming HiFi from Tidal) was more to my taste.
So far I've only listened to the stack for like 6 hours, but if I notice anything else, I'll post it. This is my first foray into HiFi consumer audio stuff, so I'm enjoying the experience of trying the new stuff and seeing what everyone's talking about!