I think the gyst here is that those who optioned SSP are pretty (or really, really) happy with it, and while not many have had the experience to audition the base system, those who optioned it seem (like myself) to be pretty (or really, really) unhappy with it. Also, see this
previous thread I started recently with similar gripes specific to the base setup, which the OP may find worth wasting a few minutes to parse.
Throughout these discussions, there are definitely valid points regarding garbage in/garbage out of source material, and I 100% agree that a good sound system offers a balanced presentation across all frequencies without bass over-emphasis. I actually feel that most car audio systems are guilty of scooping the low and high frequencies to give a false sense of definition and "richness" to compensate for actual fidelity. Despite this, and having been an freelance audio critic for the last few decades (a great intro to promptly clear a room) with way too much time invested in experimenting with different sources, file resolutions, balance/fader setting, eq settings, and different recordings/genres with my base system, I will humbly express that it's pretty mediocre with high-quality sources (flac files, lossless Tidal), and inexcusibly bad with low-fi (SXM, lower-res streaming/BT). It's a pity I hadn't had a chance to audition it before spec'ing my car since there weren't any local cars optioned with base systems, as maybe I would have taken the SSP upgrade a bit more seriously despite having little interest or application for atmos. Too bad since the relative silence of an EV cabin is a great environment for music listening.
So, I suppose this is a wordy confirmation for my fellow base (not bass) heads that you're not wrong for being underwhelmed by the stereo. You would be wrong, however, if you're underwhelmed with any aspect of actually driving the car
After all, most race cars and roller-coasters don't even have stereo systems, right? Right? RIGHT?!?!