Creating a simple QtQuick2 app with Creator, the render performance is really poor.
Build from 5.4.0 branch with -release -opengl es2.
The animation in the example app shows about 3 frame/position update during 1000msecs.
Setting QML_FIXED_ANIMATION_STEP or QSG_FIXED_ANIMATION_STEP to "no" doesn't improve the situation...

import QtQuick 2.3
import QtQuick.Controls 1.3

ApplicationWindow {
visible: true
width: 640
height: 480

Rectangle {
id: redRect
width: 200
height: 200
color: "red"

MouseArea {
anchors.fill: parent
onClicked:

{ if (parent.y > 0) twoAni.start() else oneAni.start() }

}
}

PropertyAnimation

{ id: oneAni target: redRect property: "y" to: 1000 duration: 1000 }

PropertyAnimation

{ id: twoAni target: redRect property: "y" to: 0 duration: 1000 }

}