The Xenos uses a modern unified pipeline architecture.
Intelligent Memory” (eDRAM) makes anti-aliasing an easy work.
That is why the Xenos wins. With the unified shader, it can run at near 100% efficiency. The RSX is only 50%-60% effcient when used in games.
There is a reason for the general lack of anti-aliasing in PS3 games. The RSX isn't powerful enough. The Xenos can handle it with almost no performace loss due to the eDRAM doing the work.
Then there is the issue of the unified memory on the 360, allowing more memory (with tradeoffs) for graphics. That's why some PS3 games have their resolution downgraded from the 360 version.
Yet, today, America's leaders are reenacting every folly that brought these great powers [Russia, Germany, and Japan] to ruin -- from arrogance and hubris, to assertions of global hegemony, to imperial overstretch, to trumpeting new 'crusades,' to handing out war guarantees to regions and countries where Americans have never fought before. We are piling up the kind of commitments that produced the greatest disasters of the twentieth century.
— Pat Buchanan – A Republic, Not an Empire