Originally Posted by Amputate Your Head

You can use the laptop's screen for free.

It's not all about quality, it's about convenience. If you have a MBP and work at an actual office, you can have one of these at the office, one at home, and just shuttle your laptop between. (consistency between locations, and everything is still on one system, so no syncing = time saved) This thing also powers & charges your MBP while it's connected, so you don't need to pack a power supply cord unit with you. Convenience co$t$.

You can always get a $180 buck monitor and carry that along with your laptop I suppose, or just use the laptop screen.