I personally found there was a huge difference between the stock and the hifi sound systems in the Tesla. Back when I was test driving (in May), I did a back to back sound system test, using my bluetooth paired phone, and the difference in quality was very noticeable, especially on the mids and lows, and the sense of depth. Using a USB drive I can only imagine would be even more noticeable. The stock was was definitely worse than my 2008 Audi A3's premium sound system.
One thing I will say is that the Dolby surround sound they've got often makes the music sound significantly worse. I could see some people who left that one being put off, and blaming the speakers themselves for what is a separate issue (I always leave the dolby off in my car).
One thing I will say is that the Dolby surround sound they've got often makes the music sound significantly worse. I could see some people who left that one being put off, and blaming the speakers themselves for what is a separate issue (I always leave the dolby off in my car).