I have been using only the 6 channel 5.1 audio for my burnt dvds. When playing out of a 2 channel system it seems to play OK, but I have heard from others that it doesn't? I am wondering what most are using for their movies. I know I can burn both formats, but I want the highest quality video also. Does anyone know about how many megs that 2 hours of 2 channel will add the dvd??