I have a feeling you didn't actually read the wall of text.
Yes, myself and everyone in the house can easily tell the difference between the two setups, as can 99% of people in the world. Otherwise this entire forum and every review would be "there's no audible difference between these products", the entire audio scene wouldn't exist if everything sounded the same and had the same audio quality.
One is Spotify 320 compressed stream via Chromecast RCA in to an entry level onkyo ab and out through rear ported dali zensor.
The other is lossless flac through roon via a modern dac in to a good class d and out through front ported triangle borea.
Of course it sounds audibly different.
This is why there are a range of different products made and purchased, because they sound different, better, worse.