And I have an American twang myself. I am willing, however, to say that my accent is not suitable for the language of the Lord of the Rings, as I've stated before.
Twang is subjective.
I happen to live in Texas, and I have the most neutral American accent possible, but it is still not appropriate. There is still a twang that makes it different. Jackson is going to put a mish-mash of accents in there with little thought as to why. It's one thing to assign certain accents to certain races. I still don't believe that is the proper asthetic, but at least there is a rationale and at least there is consistency.