He was pretty amazing and deserved to win. However, I'd be interested in knowing what the rest of the acts were like.
I'm not sure why we don't get acts like that on the show here, but there are a few factors that may be involved.
1) American society in general is culturally void
2) The U.S. is so much larger than Britain with so many more submissions, the gems are much harder to find. This is really me being devil's advocate, because I know that is not true. There are a lot of awesome acts that were fawned over by producers at their initial auditions, yet still didn't make it.
3) Simon and Piers have far more respect for their own countrymen (which is understandable)
We did have at least one operatic singer audition via video submission that did make it. Check out my friend Dorothy Bishop
http://www.path2fame.com/showthread.php?t=902,Matt