you should be comparing the crystalsky to an ipad, tablet or phone. As m0j0 has said it is a screen not a controller, and the SC is a controller that does not require an aditional piece of hardware in a screen.Doesnt have to be a transmitter. A Crystalsky is backwards compatible and easy to use.
Can i use my Mavic pro controller with my spark, phantom, inspire or air? If all of DJI craft where compatable with one controller it would save us all a lot of money as i wouldnt need to purchase a controller with my drone everytime i get the newest.