I like the PS2 controllers shoulder buttons more then the Dualshock 4's, but I like the quality of the 4's shoulders buttons better then the 2's.
Ultimately, if they did a remake of the PS2 controller for PS4/PC with better quality shoulder buttons that would be great. I think the Dualshock 4 has better quality button switches, the PS2 shoulder buttons need to be more durable. I wish they made over all better quality controllers period, a PBT omron switch controller would be totally sick. Their are $50 PC mice that are better quality then Dualshock controllers, controllers are overpriced for the quality you get.
Their is a market for higher quality controllers, take the PS2 controller, give it something equivalent to the quality of Cherry Red switches on a keyboard. Now your applying the same amount of pressure on the buttons, but getting a more responsive, and far longer lasting switch powering the button.
A stick is where it is at ultimately, but most MK players including myself prefer a controller for MK. If I played SF, I would switch to a stick, and then I can only assume that I would transition to using a stick for MK as well.
