Both of these formats have similar tech specs. I went to my local harware store and asked them to play the same movie "Underworld" on both systems Blue-Ray and HD DVD. They both look similar on 1080p HD Plasma TV, but Blue-Ray looks a little bit more clearer and sharper. If both formats look so similar then whats the point of having two different?I mean when DVD came out it was clear that it will replace the old VHS, but these two are hard to tell. Can someone please tell how to tell the difference and pick the better quality one?2. Why haven't PS3 fully utize the Blue-Ray dics? It has 25 GB on single space and 50 GB on dual layer.1. What is the real difference between them?