Racers, sports games... These are usually the genres that look the most impressive and run smoothly, yet with both the 360 and now the PS3, none of these genres are knocking anyone's socks off in the 'looks dept'.
I love me some RR6, but it's hardly a leap compared to other last gen racers. Same goes for what we've seen of RR7.
The road textures in RR6 were very detailed. The controller even rumbled when your wheels traveled over road/bridge segment joints (for lack of a more accurate term). The road textures in RR7 don't look finished in comparison.