I'm running the latest driver (as of 6/29/15) of the Intel 7265-AC wireless card. As of this writing, it's 18.104.22.168. Oddly, the connection to the Unifi access points (Unifi-AC and standard Unifi access points) drops intermittently. I still have an IP address, but I can't ping anything on the network.
My fix at this point is:
Ad Hoc QoS Mode - WMM Enabled
HT mode - HT Mode
U-APSD support - Disabled
I'm testing this fix (documenting what I've seen here):
(this is where I got most of the info from)