Has anyone had experience using a USB display adapter for multiple monitors on a Macbook Pro? I have a 2011 15" MBP that has 2 USB 2.0 ports. I have looked at several adapters but the ones I saw said that they require USB 3.0 to get a 1920x1080 video output. Does anyone know of an adapter that will output 1080 using my USB 2.0 ports? My external monitor has both the VGA and DVI ports so either one is fine with me. Also, how do these adapters perform? Is there any lag?