Same here I found this out after playing Prologue last night It's amazing how much more I enjoy the realistic physics of the demo TT compared to Prologue.
Now it doesn't seem like I'll have much to play until GT5 comes out
+1
Can't go back to Prologue after playing the TT. You just feel so much more connected to the car and the road, you can feel the limit much better than in Prologue, where IMO the car seems to always be too "flat" and drive on ice.