I have the same issue on my Acer Extensa 4220 laptop with integrated Intel graphics GMA 3000.
The unity on the LVDS (1280x800) works very well (Dash, window moving and effects) but on both LVDS and VGA (1440x900) it works slow.
I can show more info if you need to resolve the bug. Moreover I can help to developer to test a latest code.
I have the same issue on my Acer Extensa 4220 laptop with integrated Intel graphics GMA 3000.
The unity on the LVDS (1280x800) works very well (Dash, window moving and effects) but on both LVDS and VGA (1440x900) it works slow.
I can show more info if you need to resolve the bug. Moreover I can help to developer to test a latest code.