I didn't like how fast my Dualshock 4 analog sticks were wearing out at first, like only a month after I bought it I was noticing considerable wear on the rubber. So I bought some KontrolFreek sticks to put on them, mostly for protecting the life of the controller, but they also happen to improve aim and control in most games, especially FPS games. I ended up getting the CQC signature sticks since they added minimal height to the sticks and were easiest to get used to. Though after about 8+ months of heavy use, even the CQC sticks have started to come off their base, making me apply superglue to the rubber to re-attach it. Still for $10 a pair, 8+ months of daily use isn't bad.
Anyway, I am about to order some new ones, this time I will be getting the taller ones where the rubber is wrapped all around the top part so it won't come apart the way the CQC sticks have over time. And being used to the height of the CQC sticks already(which was really nothing to get used to), I don't think it will be very hard to adjust to the higher ones. I haven't decided which ones to get yet, but I'm leaning towards the Ultras, might get a convex and a concave set so I can experiment with having them on different sticks. Like the Vortex ones they offer, where the left stick is concave and the right stick is convex.
Another accessory I find useful is the Move Controller. I play Just Dance games once in a while and while the camera works alright for the games on PS4, the move controller by itself is far superior for more accurate detection of your dance moves. Unless you have perfect lighting conditions for the camera, it will be quite frustrating trying to use it on a game like Just Dance, especially if you are used to the accuracy and reliability of the move controller already.