Screen color
I can confirm that the screen brightness/contrast/tint seem to have been altered in GRI40. Like the other posters, one of the first things I noticed.
The latter two seem to be the real problem, in my eyes. The color tint shifted towards yellow, making colors look funny. The contrast seems to have been decreased, washing the screen out, which seems to spread the yellow tint everywhere and make it much more noticeable.
My screen was beautiful and contrasty before, now it's washed out and yellow.
Interesting that the "Google" logo that shows up when the thing boots still looks great.
Not until the OS comes up does the screen look bad.