What about Halo: Reach though? I am pretty certain that you at one point believed this to be the technical pinnacle of 360 game development as well..
Newb, you have been here 4 months and have less than 200 posts--you were not even here when Halo 3, ODST, or Reach were released (at least not under your current ID). So do the courtesy of quoting something specific because I know Acert93 and "antwan" have never engaged the topic and I am pretty sure you are distorting things I have said.
What I have said, repeatedly, concerning the technology in the Halo series is that there are a lot of games who simply look at visual check boxes and equate that to technology. There is a lot more to a games technology than such. I have argued that it is a gross distortion to ignore the laundry list of features and technologies found in Halo titles (match making option, a full theater replay mode, map modding, 4 player campaign cooperative play, 4 way local split screen, large sandbox gameplay, solid AI with a fair number of players on screen, etc) as trivial and irrelevant when discussing "technology." Game development is about compromises. It is really easy to comprehend when comparing 2 game's divergent design goals:
Game.A // Game.B
4 player coop // No coop
split screen // no split screen
large open spaces // narrow, smaller game spaces
many enemies on screen // 2-3 enemies on screen
dynamic AI // heavily scripted AI
replay mode // no replay
low load time // frequent load screens
These design choices impact what technologies and resources available. To ignore such and move right into what graphical feature is/isn't available, render resolution, polygons, or whatever as the benchmark of "technology" is niave for some and straight up Halo/Xbox hate by others.
It doesn't mean the choices were good or right or even the best compromises but it is an immediate impasse to intelligent discussion.
The fact you cannot spot a single technological improvement aside from resolution is a pretty telling.