I understand that the limitations of thunderbolt and other macs doesn't make it possible to drive the display via TDM at 5K. But why don't they simply lower the resolution of the display when put in TDM? I can't think of a reason that they couldn't have worked that feature out. But I understand that it's not top priority and that they wanted to get it out there. I wonder if it's something that can be made possible through software updates however? But knowing Apple they would most likely release a new iMac with that feature instead.