Originally Posted by Doug Pardee
Here's a photo that someone made of 1.4 and 1.5, showing both the darker background and the bolder type:
These pictures were taken with different aperture and exposure settings. Additionally they were taken with automatic white balance. These pictures don't tell anything about changed contrast/brightness/darkness, but a lot about the photographers skills.
The brightness is unchanged (it's impossible to change the brightness anyhow on eInk screens).