@nrs
Yea, unfortunately that's what I have noticed about wifi in general, it's rather difficult to know what you can actually expect. Perhaps, if one of your friend has a laptop with 802.11ac, that you can borrow and try? I know some of the newer mobile device (iPad and newer iPhone, Android) has the 802.11ac capability as well. Although once again, I don't know how they would compare between a laptop vs mobile device.
I recommend you put Ethernet if its possible, that's the only way to really get everything out of the giga speed. Ether way, enjoy your faster speed