The voice recognition is great. You don't need a controller in hand. "Xbox pause" "Xbox play". "Xbox go to Netflix." Are all extremely convenient. Also if the room is wired for cable or dish you can plug the HDMI into the Xbox and use voice controlls for that as well. "Xbox go to TV" "Xbox watch ESPN."

As far as gaming goes I would recomment a wii U for kids that age. But the Wii U doesn't have bluray, and the netflix app is garbage. For some reason it is worse than the app for the Wii. It doesn't support different users and it won't save your place if you leave a show and come back to it.

Another feature of the Xbox one that I like is that you can listen to full game audio by plugging headphones into the controller. (headphone adapter required) This way you can play late at night without making any noise. Sounds like this might not apply to your situation, but I like it.

I don't have any experience with the PS4, but from what I understand it was designed primarily to be a top notch gaming machine. The Xbox One was designed with multimedia in mind.