GT has never been and never will be as realistic as LFS.
However, it has always been one the better console racers physics wise. Making it a sim-arcadey racer.
It also makes up for it's poor simulation with what is an encyclopedia of motorsports, cars and tracks.
The number of cars is amazing, you can highlight brands and it'll give you a brief history. In the setup menus, it manages to give an easy to understand explaination of different setup options. The options for setup are vast as well. Especially for a console game.
It may not be very accurate as a driving model. But it makes up for it.