The interior improvements are incredible. What a huge difference. I had custom dds files loaded for all of the cars before, but I think once all the cars are done I won't need them any longer. The race cars are great, but the XFG is probably the biggest improvement. It looks much more crisp, clean, and realistic. I can't wait to see the rest of the cars get the improvements as well.
The XRR headlights do look a little odd, though. As though the texture doesn't quite fit or something.
I haven't had a chance to test out the frame rate improvements (my work machine doesn't support HVS), but so far the patch looks superb.