Has anything changed substantially between the games? They look the same.

The frame rate drop is a glitch in the demo. One that I dont expect to follow to the full game. If you change the screen size to 90 percent it goes away

No they don't look the same. GT6 looks better. Trust me, i play GT a lot and was getting warmed up for the academey on GT5, the switch from 5 to the demo is noticably different while keeping the feel of GT.

Is the AI really this bad?

GT6 looks darker, but that's all I can tell from the pictures.

How many new tracks does it have compared to GT5? The movie in the OP, that track looked identical in both games.

lol

What I noticed while playing the GT 6 demo:

Faster load times - By about 1,000%

Better lighting - Here is the biggest improvement I saw to the visuals, shadows aren't as pixelated, and the lighting is just far more natural.

Better physics - I noticed that the cars lean depending on where the weight is, and how much you turn. A little touch, but very cool.

doesn't look so much better to me, but I can see improvements between GT6 and GT5

Illumination and shadows have improved, and physics too. Is a notable advancement, but what i wanted most, was improving the IA (races with IA rivals are a joke) and engine sounds, and those are still work in progress....