Mac Book Pro/OSX 10.7.5Same room.
5 feet distance.
5Ghz Single mode N, WPA2/AES only, USB 2.0 selected using USB 3.0 1Tb USB drive.
6-7Mb Write
9-10Mb Read
5Ghz Single mode N, WPA2/AES only, USB 3.0 selected using USB 3.0 1Tb USB drive.
6-7Mb Write
9-10Mb Read
Not sure if the router was doing anything to the drive as it drive activity like was going before and during the actual xfers. Could be some router processing effecting some performance.
I can't test AC since the adapter I have doesn't work on MAC...yet.

No differences seen.