A bit of a coincidence this thread cropping up. I've just seen my first Blu-Ray DVD today and had my first chance to compare 2 versions of the same film...... OK it was Disney's Pinnochio, which is a lot older than even I am, but it was the only film that we had both versions of.
I'm unsure if I could see a difference between the 2 versions or not. I was so wanting to see if there was a difference I think I ended up with spots before my eyes trying to convince myself there was.
What I do know is our kids enjoyed the non Blu-ray version before we (allegedly) adults got into the dvd/blu-ray discussion.
My mate could tell the difference. Well he claimed he could and I watched his nose very closely for signs of growth.....