I just purchased 4 DDJ-SX3 controllers a couple of weeks ago for myself and my DJ team and out of the 4 I purchased, so far 2 of them have had some major issues. Here is what I've experienced with the two controllers so far:
-Headphone cue lights stop working for no apparent reason
-Volume levels increase and decrease on its own
-Headphone cue button suddenly causes one of the songs to restart to the beginning of the song. Almost acting as if it was a cue point button
-All of the lights on the controller would shut off but the music would keep playing
-Music becomes extremely distorted, making the speakers sound like they're blown.
-Song start jumping to different parts of the song automatically without me even touching anything.
-Song would restart to the beginning of the song by itself.
This starts to happen about an hour or so into the set. I'm using Macbook Pros with either Sierra or High Sierra, newer models, with and without Touch bars on them. I'm going to assume that it's more of a firmware update issue I hope. The odds of me getting not one but two defective units seems very odd to me. In any case, I've shipped one back to Pioneer already and waiting for my replacement. I'm going to send back my second one also just to be on the safe side to see if maybe I somehow did end up with two defective ones. I'll keep you all posted but I would definitely wait for a while before you decide to buy a DDJ-SX3 until they can work out all the bugs.