QML QtQuick2 (Qt5) Text looks blurry, and twinkles when animating

It was fine when I was using QtQuick1.1(Qt4.8.3), but it goes not so good when migrating to QtQuick2: the text looks blurry, and it will twinkle when animating.

My Code:

import QtQuick 2.0

Rectangle {
width: 700
height: 32
color: "black"

Text {
text: "Go! HappyNewYear! Nice! Come on!"
color: "white"

NumberAnimation on x

}
}

Add renderType: Text.NativeRendering will solve the problem.
But I don't know whether this undocumented property will bring any new problem.

I also posted a thread on the forum:
http://qt-project.org/forums/viewthread/23559/

And a related thread:
http://qt-project.org/forums/viewthread/23563/
(I don't know about OpenGLShader, but it said 'warning'..)

And when discuss with epicfailguy93, we found that the Text in QtQuick2 is slower than QtQuick1.1
http://qt-project.org/forums/viewthread/23566/

I uploaded the screenshot in QtQuick1.1 and in QtQuick2