Dave,
480P into the component inputs of the P50 from a good DVD player
is great. 720P into the DVI input of the P50 is greater!

I don't know
how much work the P50 does when it is fed a 720P DVI signal compared
to feeding it either a 480P signal via component or 480P via DVI.
I can easily try and see how much difference in PQ there is with 480P
and 720P via DVI. From what others have said, the advantage of DVI
is that all the data "conversion" is done in the digital domain and stays
there all the way to the display. With component, there's a switch
to analog and back that's needed.
So, I would think that with DVI input there's much less work for the panel
to do. For 720P it would just be a matter taking 1280x720(?) and
upscaling it to 1366x768 in the P50.
Now that I have the D1, I could use a DVI switch, too, if I want my Zenith
520 to connect via DVI. Cheapest switch I've seen is the same price
as the D1! Currently, I don't need DVI/HDCP from OTA HDTV. I haven't
upgraded my dish yet. (that's another story...) . So I can afford to wait
a bit for a DVI switch. I would wager that once you saw DVDs via
DVI on your 433cmx, you wouldn't miss DVI on your stb. Is there
anything now that requires DVI/HDCP on sat?
The D1 is basically a replacement for HTPC-DVD. So for the price of
a D1 ($200) and the price of a Dr Bott DVI switch ($200), can you
build a HTPC for DVD? I would say, "no". Not to mention the savings
in space and heat.
larry