I just dl the trailer from XBOX Marketplace. I found that the quality is not so good for HD. It seems to be like a upscaled DVD. Does the HD DVD really better than this? How much better? Worth the purchase for this? (i think the first one is the best and the second one or the third one is ok).
Any advice?

I downloaded that trailer too and trust me when I say the HD-DVD's are definitely better.

I just dl the trailer from XBOX Marketplace. I found that the quality is not so good for HD. It seems to be like a upscaled DVD. Does the HD DVD really better than this? How much better? Worth the purchase for this? (i think the first one is the best and the second one or the third one is ok).
Any advice?

First take a moment to just scan at least the first page before starting a thread. We have so many threads/polls discussing the PQ of this title it's almost too much. For example here is a Poll/Thread a couple down from yours discussing specifically the PQ of this title.

http://www.avsforum.com/avs-vb/showthread.php?t=850661