Spencer,
The more you can protect the lens from stray light (such as hairlights, but also just plain ambient light), the better the contrast can be preserved. This will help with color saturation and with details in the dark shadows. Granted, with todays anti-reflection coated lenses and filters, it's not as big a deal as it once was, but it still helps some.
Also, most matte boxes can take 4" x 4" filters. Some of those filters are graduated (maybe dark at one end, or sky blue at the top quarter for those overcast days). And usually one of the filter stages will rotate, allowing easy adjustment of polarizing filters.
And if none of the above interests you... well, just think how awesomely professional you'll look with some big ol' matte box hangin' off the front of your camcorder! :-D
Ken Hull