I like the "hollowness" of sound you get with a closed canopy, but are you planning on removing the plastic to get a more clearer picture? you could cut out the plastic and leave just like "windshield frames" so you'd see clearly, but get the feeling of being inside of a canopy. That's what I'v seen people do a lot. I think on one Flitetest episode they mention that too.
Well I don't really care about how "clear" the image is, but sun glare might be problem at certain angles on a sunny day. I like to see the pilots footage too. Do you have a recorder to record the ground footage?