I'm coming from a custom built system in my last vehicle and audio/video is my career, I'm a commercial multimedia director out in Dallas, and brought several of my own reference materials to the car for testing. Audio and video are basically my life (though much more on the home theater side). The system sound is fine for most people, i fully recognize that, but I feel it very much lacks what I want though, and it has nothing to do with the source. The 3 slider EQ is extremely problematic as well, boosting the treble even one notch causes an upper level clipping to occur, if you listen to a lot of classical or soundtracks it completely kills it (exaggerating, but its a subtle details that is lost). Lowering it has an extreme steep drop off that goes from overly bright to suddenly too thin and no bite at all, no middle ground. Upping the mid section instantly muddles the sound, some people might like it but its too pronounced and has almost a sharpening effect to it.
Everything I am talking about is subtle, but I notice it immediately walking out of my office setup in getting into the car. I'm super picky, its not a fault with the system or car, its rather I have a higher expectation for it than what it can achieve in its current state. But I'm going to fix it and make it perfect!
Absolutely agree with you.. I'm coming from a $6,000+ custom system on my last vehicle.. And the JBL is noticeably crappy compared to it. The mids, highs, mid bass, bass all are lacking. It's missing the "wow" factor.. I'm sure there's plenty of people who are satisfied with it, but when you've heard something far superior, there's just no comparison. I'm just replacing the stock sub and adding an amp for it with converter for now... Once there's some good head unit options, I'm gonna replace everything.