I loved my LS 430, however it was terrible to drive on the hilly and winding roads of North West CT in the winter because of its rear wheel drive. The 430 has a superb ride - the RX ride is not quite as good but better than I expected. All in all I am very happy with the RX and believe it to be a better value for my money than the LS 430.
My four wheel drive RX zips around in the worst weather. Great Lexus quality and reliability. I had a Levinson system on my 430 and do not have one now - I cannot detect much difference in sound quality. It was nice to save about $4,000.
The rear view backup camera is great, however images are far more distant than they really are on the screen. The retractable cup holder to the left of the steering wheel obscures the buttons to open the back gate and gas tank when deployed. Side cameras for parking in tight spaces would be nice.