SiriusXM has an extremely low bitrate, something like 48kbps per channel, so I'm surprised it'd sound better with a better sound system. The difference would definitely be noticeable with a high-quality audio source (like songs in lossless FLAC format via TIDAL, Qobuz, Apple Music, your own Plex server using Plexamp, etc)As someone who listens to the stereo on a daily basis (Spotify, Sirius XM etc), it really blows the Bose out of the water
I'll have to see if any of the local dealers have a car equipped with it, to try it out. I'm not an audiophile so for me personally I'm not sure if it's worth the price.