Lush, sorry for the lag in response, been busy tubin. The short answer is no. I have not made that particular comparison, Apocalypse Now was always one of my favorite LDs. Your point about 5.1 vs. PCM 2.0 remixed into 4 channel is a good one however. Truly difficult to make an apples to apples comparison there. As 7.1 is the order of the day and HD quality video is vying for space with audio on a single double layer disk audio compression will always be a concern.
I doubt we could ever reach a consensus on the comparison mainly because LDs have fallen so far out of the mainstream. I would say this however. Any format that requires me to get up and put in the second disk to finish watching a movie hearkens me back to the first time I heard an 8 track tape switch tracks ( in Dark side of the Moon, it was an abomination). Though the sound may be better (if we could come to an agreement on that point which I'm not sure we have) I just can't get past the interruption. I feel the same way about the new 45rpm vinyl editions. I own a few and they sound fantastic but it's too interuptive to have to change the side every few songs. I try to look at movie enjoyment in it's entirety. In home theater the sum of the parts has to equal a worthwhile experience. If one of these parts is disproportionately lacking in quality such as to detract from the enjoyment of the film I don't deem it worth MY time and money to build a system around it. Others might disagree.
The music/audio portion of my DVD Blueray based home theater system has never once made me yearn for the long lost Laser disk days of yore. I'm an audio snob, I freely admit this. The quality of current audio simply does not draw adverse attention to itself in my system. Quite the contrary, I find it quite satisfying. That is the litmus test for me. It's why I still love vinyl and finally got into tubes. There are some things that refuse to die, laser disks just do not seem to be on the list...