I am just looking forward to using the DS4, from what I have read and seen the whole feel and redesign of the controller and especially the triggers and the analog sticks are what interests me the most, as for the touch pad it’s a neat idea and it will be if devs can integrate into their games that will make it useful or not.
Watch dogs appears to make good use of it:
Today we played the game on a PlayStation 4 controller, it’s also a very tight controller, and we really were happy with what we saw, it’s relatively new still for the team, but it’s a great controller. And we’re also making use of the touchpad [on the DualShock 4] which we think is a great addition because we have, well, Aiden spends his time using his smart phone so he has a direct reflection of those inputs on his controller.
http://www.playstationlifestyle.net/2013/05/10/watch-dogs-developers-on-ps4-are-able-to-push-further-every-aspect-of-the-game-dualshock-4-touchpad-discussed/







