Are any of the 2012-2015 retina MacBook Pro displays different?

My friends macbook pro is a 2012 retina, mine is a 2015 retina. when i saw his beside mine for the first time, i saw that my screen seemed a little better in some way. As if the contrast ratio was somewhat better. On all the retina macbook pros, are any of their displays different? Not including 2016+.