And finally, shooting in HD will still give you better quality than just shooting in SD. From how I understand it, shooting in HD captures more information than SD would.
Let's be clear and not confuse pixel count with information. HD formats have more pixels but not necessarily more information than SD formats. It all depends on the flavor of the HD format. For example, HDV contains LESS info than DV.
This is why. HDV has the same data rate ( ~3.6 MB/s) as DV. It operates at the same color bit depth. So to get an image that is greater than 4x the pixel size of DV down to the same data stream size, some serious compression is taking place. Once the material goes through that compression in the camera, the information is lost. Aside from the image hit, the material is recorded in a very problematic format (mpeg2 based long GOP structure).
To get HDV to look good you need to understand the limitations of the format. Any noise introduced through small ccds and low light simply is magnified during compression. Any fast motion generates blocky sections as the compressor must keep the data rate down. To work around these limits means slow and steady camera movements and very well lit subjects. (good advice for anyone looking to create crisp and detailed images) Keep within the limits of the camera and format and it is easy to record good stuff. (Still, HDV doesn't make it easy to edit and/or compress for DVDs though!).
Cheers,
x