Got my copy of the game for Christmas. Only one that I don't own is GT2. Have to say it turned out very well. I absolutely love how they went back to their roots and took the original tracks and names of some of the races. When playing clubman at night it reminded me of playing the track 10 years ago using my Impreza. It's amazing how well you remember the track even if you haven't played it in years. It feels like you're reliving your childhood almost
(now that I think about it some of that might have been in GT4 as well)
There should be plenty of new content that I haven't tried either. Didn't even know they had karts in the game. On top of that NASCAR, and also being able to play dirt tracks. It just seems so weird because it's probably been almost 5 years since I played GT4.