I have some old movies on Blu-ray several John Wayne films as well as
Gone With the Wind all of them are for better than there DVD counterparts.
It all depends on how much the company/studio puts into the transfers of the films etc. on what they look like.
I'm a member of a website called
Blu-ray.com you can find screen shots and reviews of practically anything released on Blu-ray.
Here is the review for
Point Break "Pure Adrenaline Edition"
Point Break Blu-ray: Pure Adrenaline Edition Released on Blu-ray in 2008.
Pitch Black Unrated Director's Cut
Pitch Black Blu-ray: Unrated Director's Cut | Chronicles of Riddick Series Released on Blu-ray in 2009.
I was slow in getting on the Blu-ray bandwagon only get my first player last Christmas but since then have slowly been converting a lot of my DVD titles to there Blu-ray counterparts.