Not sure what video you're trying to show, but the Epic Citadel on my phone isn't quite that impressive. Maybe it's using a few tricks that didn't show up until Gears or something, but it's pretty obvious that it doesn't have a heck of a lot of texture memory to play with.

My demo also doesn't have a single character anywhere in it. I'm sure those early 360 games would have looked nicer if they had no enemies or characters at all.