"HDV 1080i would be 1440x1080i (anamorphic, so it's still 16:9 aspect ratio)."

Thanks - I tried it... again no discernible degradation (at least not on my monitor), and a significantly smaller file size, but the same 4 scenes (75 seconds) took 6 mins 15 secs to render on my machine.

At least I have something to work with.   Now I will go back to the advice on another thread on here regarding burning DVDs in HD quality, for either blu-ray or DVD players.

I'll run a couple of small projects like this until I get impatient, and willing to spend some cash, and maybe buy a new PC with a blu-ray burner.  

Working my way up...  but it's good to learn along the way!