It's supposed to upgrade the textures. I don't know if it works, though.
Just in general or because of the texture bug?
It would be cool to get confirmation if there is or isnt a visual benefit for installing the game.
In the description for the 1.2 patch there is this line:
"Fixed issue where textures would not properly upgrade when installed to drive (Xbox 360)"
which I'm assuming is in reference to the texture bug and not an actual upgrade in the visuals. Plus anything that enhances the experience would usually be advertised right?.