Trust me (or look it up:
http://en.wikipedia.org/wiki/DV) miniDV is a compressed format. It's clean because it is intraframe compression and does not use neighboring frames to predict motion, but it's compressed. HDV "can" look quite clean. The deal is, when you dump it to some editors, they store it in a format that can be cleanly edited, which is hard to do with the mpeg formats since mpeg uses predictive frames and delta frames. Some editors are able to work with the native file format and don't require the conversion process.
Once you get the video to your computer via firewire, you can save it in a non-lossy format which will allow you to edit and archive it at full resolution. Quite frankly, I've steered clear of these issues and I'd rather shoot HD with a different format. Even with it's limitations, the Panny HVX would be my first choice if I wanted to do it for a reasonable cost.