are you kidding?
the FIRST Forza had better damage modeling and impact physics.
the only reason GT5 will not be a COMPLETE failure is because they have so many retarded XBOX hating fans.
I used to be the biggest GT junky, played the Forza DEMO and realized in 2 minutes of playing it what the superior game was.
GT was AWESOME until GT4 where it started its downhill slide into failure.