There may be other factors at play, Apple quite likes to compress stream data between their own devices, even on “standard” protocols (just look at their monitor collaboration with LG where they did the same thing to exceed the max resolution of an existing display signal). Regardless, there is a difference, and it is not a small one. It was immediately obvious to me after listening to a single song. Something about the pipeline is crunching audio to the level where it’s obviously degraded. This isn’t audiophile grade splitting hairs and “I think it sounds ever so slightly better with these gold cables” it was like the difference between 480p and 1080p video to me, enough to be actually annoying during normal listening, even if I was actively trying to forget about it.