Practically speaking, they were mostly an apple only liability. Go to any podium with an apple laptop made before retina when they finally caught up with the worldand stuck an HDMI port in the macbook pro, and you will find the DVI/VGA/HDMI cable that everyone uses, and no way to plug in your macbook if you forgot your 3" dongle. During presentations in undergrad, everyone with a macbook had to email themselves or use a flash drive to bum someone's better endowed laptop to hook up to the projector, because no one ever accounted that they would need a $30 dongle to use the video out on their $1500 laptop. IT started buying these miniDVI or whatever dongles for the podiums, but they wouldn't stay put for very long in the lecture halls.