So I ordered this USB 3 sync/charging cable and I ordered another brand USB 2 sync/charging cable. Both showed the fast charging. I don't know if it's my phone, but plugging in USB-C one way does fast charge, but the other way shows slow charge and it's happening for all cable, so cable-wise, it seems to be charging as any others.I did a data transfer test of transferring about 1.5GB of data. Transferring data from PC to the phone, both this USB 3 cable and the other USB 2 cable took about the same time. But transferring data from phone to PC, this USB 3 cable did take half the time than the other USB 2 cable took. So this cable does seem to function as USB 3 data transfer cable.Again, this may be because of my phone, but for both, connecting one way in USB-C to my phone, the computer recognized my phone and connection was stable. Now if I flip and connect USB-C end to my phone the other way, the computer did not recognize my phone for both this USB 3 cable and the other USB 2 cable. Though one of this USB 3 cable did recognize the it kept disconnecting which is no better than not recognizing.So in summary, this USB 3 cable does seem to give faster data transfer speed than USB 2 cable when transferring data from phone to PC. Connection to PC works and is stable for one way, but not when I flip. It does fast charge the phone one way, but when I flip, it does slow charge.So if you will be transferring files from phone to PC often and a lot, this USB 3 cable is worth it. Otherwise, it will be waste of money.I cannot tell how long it will last since I just got this today, but this cable is thicker than the other USB 2 cable I got which is positive.