Shown below are screencaps from National Lampoon's Christmas Vacation. The transfer isn't anything amazing, but if you're looking for something better than your DVD version, this is it.
In this sequence, there is noticeably more grain than usual.
If we look at the full-resolution screencap, we'll notice a soft and somewhat grainy image. This is due to the camera's focusing point. In the first screencap above, Chevy Chase is coming out crystal clear. This is because his face and the focusing point of the video camera, are the same. However in the image below, his face is away from the focusing point, leading to a perceived "grainy" image. When the camera is focusing either in background or the foreground of a subject, the camera reveals the grain of the transfer because there's nothing to physically focus on.
Overall, I think cameras were placed very close to Chevy Chase because this entire movie revolves around his expressions. This was pretty much the only option, because it is very difficult to use a zoom on a camera. Using a zoom becomes problematic because then you're dealing with another issue such as depth of field, and your character's face just won't look proper set against the background.
Below is an example of the softness being used in the film. Unfortunately, I think some primary colors suffered because of this. The scene doesn't too bad moving at a few dozen frames per second, but still, the colors are muted, and focusing is off. The problem with scenes like this, is the characters are moving around so fast, you don't have time to frame each "shot" like an "A & B" camera shot where either camera will be in focus. Today, the technique is much more disciplined, but back in the 80's, following characters from scene to scene, was a task and not entirely practiced to the point we have today.
This scene looks soft, but at the same time, given the Christmas atmosphere, the red robe Chevy Chase is wearing looks really nice in the movie, and this is one of the few scenes where primary colors come out.
It's too bad we couldn't get a more bountiful transfer. Warner Brothers packed this HD-15 disc way too tight, when they could have opted for an HD-30 disc, increasing the video (and audio) bitrates.