I've been using it for a couple weeks and It's pretty good. I've been using it in a 5GHz Network and it wont slow down the connection speed, also it is Dual-Band, so that's why I'm giving 5 starts. I totally would recommend it.
Setup was easy on Windows 10, but the performance was awful. Very flakey and inconistent and nowhere near the speeds one would expect. Mine might have been an exception but I can't recommend this adapter.
Does not work directly with the built-in Network Control Panel. Will technically see and connect to an AC AP, but packet loss is high for an AP that is 14 feet from the computer, and the resulting connection speed is less than 1/10th real world AC speeds of other Macs I have with built-in AC adapters. Worthless waste of time to purchase this for a Mac.