I only use my Macbook as-is...no external monitors. Honest question: What is so great about this feature that Apple is touting with all the seemingly problems and limited support? Why not just buy a $400-$1000 great monitor and use that for your external/extended display for your Macbook or iPad (other than you don't want to spend money)? My limited research shows that external monitors are well supported by Apple Macbooks and iPads and is far more supported, likely simpler, and should be better.