External HDTV Receiver and S/Video question

[SHS]

Sale people like let say Dishnetwork, etc all say it will be choppness, etc so is there any turth to this or just lie to try pump up HDTV sale?.
What I dosen't under stand is if this was true then why do the 99% of HD receiver all have Tuner, Composite, S-Video output if it dosen't down scale (down converting) to thoses output so why even add thoses output in the first place.
Has any done this if so is the picture quality good?.
I do have two TV that have Component input but I think there only 480 but not very useful for my PVR 500 card.

Take the Disknetwork HDTV 811 Receiver as an example will it be choppe, etc, etc if I was to used the S-Video output from the Receiver.
Dose the picture quality look good even knowing my TV set is not a HDTV set?.

Why I ask being Dishnetwork is going be add some new channel next week (10 Original VOOM HD Channels).
Rush HD
Gallery HD
Rave HD
Ultra HD
Equator HD
Monsters HD
Animania HD
Majestic HD
GuyTV HD
HD News!
So I thinking about going back to dishnetwork now that I know I can have dishnetwork here in this small apartments building .

[korben_dallas]

I don't know about the enthusiast market, but almost all of my friends and family are technology-phobic and only buy a new TV about every 5 years or when their current tv breaks. None of them have an HDTV, and only 2 friends even have DVD players (one of which I gave as a gift.)

If in X number of years, you can buy a 27" HDTV for $300, then the non-techie general public will probably start buying them en masse. Until then, broadcasters providers and operators are going to have a hard time pushing HD content. They will HAVE TO make down-scalable technology or continue producing non-HD content.