Bitrates? What are they, and how do they work?

its how many bits per second, and if its actual bits, 70 is insanely low. bits are a measure of data.

its prob mb

So is higher better as far as quality goes? I've never actually taken the time to look into this myself.

I usually forget to even look at my bitrate before rendering, and when I do, I just raise it a lot and call it good, assuming higher bitrate means more info and thus higher quality

Kind of, high bit rate in raw form the better, but taking your 24mbps footage from a dslr and pumping it up to prores 422 HQ which is like 100mbps makes it worse. Cameras like the hvx/hpx shoot dvcproHD onto p2 cards which is 70-100mbps depending on the recording setting and its higher because of the codec (which is 422 vs 420 of a dslr). So in this case, the more information in the shot the higher quality it can be. obviously like RED footage is a very high bit rate because of the high resolution and high frame rates, etc. It all depends on the camera and how it shoots.

just curious, how does this make the footage worse? other than the quality loss whenever a video is reencoded

Because you're expanding the color space and bit rate and pretty much is similar to stretching like an SD shot up to HD. Obviously, its not as dramatic as that, but its the same idea. Just use prores LT for anything on a dslr/avchd.

Panasonic's P2/DVCPROHD technology is incredible. From what I have gathered it is the best prosumer video camera money can buy these days, besides the fs100 .etc

Truely, dvcprohd has its place. But, if you're shooting for the internet or even professional dvd, 422 codec really isn't needed. I wish my fs100 was p2 or sXs xdcam, but then it would have been 4-5000 more dollars.