My DS plays Civilization on our old iPad 2 and enjoys it. We have a PS4 also, and he's good with time management and not addicted, plays a little Minecraft when friends come over, but that's about it. It really depends on the kid and the boundaries you set. If anything, he briefly got hooked on a Transformers game for the PS4, completed it, and hasn't played the PS4 for a week. The iPad is nice because they can play their school linked math games, do code.org, write and draw and also play some games. I think they get more out of that than the game console, but the multiplayer feature is nice on the PS4 for having a few friends join in.
