I've been up until now making back ups of my DVD's onto DVD-Rs. This is fine and all and I have no problem doing it. But I'm curious, if I can get a full 4gb DVD down to a 700mb Divx/Xvid file and keep it on an external disk why not just do that? I hook my laptop onto a 22" monitor which is how I watch most of my movies and occasionally onto bigger screens. How much more noticeable quality difference is there in a DVD than a Divx file? What size screen would I need to notice it.