I've got an Intensity Extreme hooked up to a 27" iMac.
We are planning on using it to incorporate live video from a Cisco C20 telepresence unit. The telepresence unit wants to spit out 1080 or 720 at 60Hz.
However, it would appear that the Intensity Extreme can only handle those resolutions at 30Hz - as we've successfully hooked up a desktop and laptop machine to the Intensity Extreme pushing 1920x1080 @ 30hz.
I can't change the refresh rate on the Cisco unit.