Seems like you've got a bit of misinformation. You could pay a premium for a frame made in the US, but that doesn't necessarily mean you get a better bike. And many people fail to make the distinction between China and Taiwan.
Given a choice, would you prefer a frame that's hand made by someone who only builds maybe a couple dozen bikes a year, or someone that welds up several bikes a day? I'm just trying to point out that country of origin does not always dictate quality.
As far as comparing materials, that would take forever to point out the differences. But here's a short primer on Scandium
, which is an element added to aluminum alloys.