Is it better than HDMI, how does the quality of the signal compare to DVI and VGA? Can it be used for a lot of things (like TVs, displays/monitors, etc.)? I have a 27" iMac, but never really used the Mini Displayport. I also haven't heard much about it (spec wise). A comparison between HDMI/VGA/DVI/Mini Displayport would be great. Thanks.