Nstreme dual is old technology, 5GHz-AC on MikroTik works good only on 802.11 plain protocol, not on nv2 and nstreme, so you won't get the speed you see in the video.
In the video you're seeing UDP speed test. With TCP it's different.
If you want full duplex I suggest you to create something similar to this:
http://wiki.mikrotik.com/wiki/OSPF_to_s ... redundancy
You'll have redundancy and speed.
But is very difficult to find 160MHz (80+80) clean spectrum to get these speeds, and your 5GHz neighbours won't be happy with that
Also, to have good stability on AC you need a directional antenna with narrow beamwidth, like the new Dynadish or QRT 5 ac.
You have to lower the power a lot as your link is very short.
SXT has 28 degrees beamwidth, far too wide for a good AC link
I think for your bandwidth needs you should choose something else than 5GHz, even MikroTik with upconverter to 17 or 24GHz can be good if you want a cheap link