We discussed having the factory head rest units installed in our Ex and decided against it. At $1,800....even though it offers a 'cleaner' look...it's just not worth the price (at least in our opinion.) We ended up buying a couple of mounts that secure to the headrest bars and use them for an iPad mini (since dropped by the wife) and a Kindle Fire. There are plenty of videos, etc out there to keep them occupied. The biggest issue we had (prior to the wife breaking the iPad mini) was trying to 'sync' the videos together as closely as possible so we could turn on the sound on one and mute the other (our kids are 2 and 4 and not quite ready for headphones yet.) If your children/riders are a bit older that wouldn't be an issue for you.
As I said earlier the factory headrest is a cleaner look, but your riders can't take them out to play games on them, take them into a restaurant (or the house, etc) as you can when using 'pads.' We achieved nearly the same results as the factory headrest for about 1/4 of the price and in the end we were happy. Not trying to steer you in that direction necessarily, just expanding on what peterk9 said.
https://1drv.ms/i/s!Ar6C28xqT5INiwTFiW3PSF4grPHZ
https://1drv.ms/i/s!Ar6C28xqT5INiwVkFTswZ-jWD9OW
https://1drv.ms/i/s!Ar6C28xqT5INiwjtFAKYttS8Qevu
Also, there are many different headrest mounts that might offer a 'cleaner' look if you wish. These weren't terribly expensive and we figured if the kids broke them we wouldn't be out much.