I recently purchased an ES300h and still own a 2002 SC430. I agree with everything Doug says about the ES300h except for the sound of the Mark Levinson system. I purposely spent a lot in order to get the Mark Levinson because it is so FABULOUS in my SC430. But I find the sound in my new car to be overly bright and the center front speaker to be so loud that it overpowers the other speakers making it sound almost monaural. I like to listen at a rather loud volume and, unlike the SC430, the volume does not go down when the navigation gives an audible message. It is very easy to miss what is said.
I have been an audiophile for many years. The SC430 has the best sound I have ever heard, even on high priced indoor systems. However, the speakers in the SC430 have a common problem (at least the larger ones in the door). After only 3 years these speakers began to distort badly. It seems the surround material on the paper speakers deteriorates and the cone is no longer centered in the driver. Lexus replaced the speaker for free since the car was still under warranty, but unfortunately the same thing happened again a year ago. Lexus quoted $300 per speaker for replacement. My service contact recommended getting it done a lot cheaper at a local car audio shop. But after viewing videos of owners replacing the speakers, I decided to hold off and haven't yet decided what I will do.
I assume ML has corrected this speaker problem, especially since they advertise the quality of their new speakers. Now if I could just get the system to sound good to my ears. I tried lowering the treble and raising the bass but to no avail. At the price of this system, why doesn't it have an equalizer?