due to the loss of orthogonality in the channel matrix, you're not going to get anything from 802.11n, other than perhaps the double-wide channels.

No, I'm saying that if you needed a wifi network for say a campsite or outdoors event, or even a private muni-sized network.

You would use a regular omni-antennae for local client connectivity in each zone then a bunch of these to provide the backbone link to connect those zones to some centrally better connected point. Rather than trying to do a pure peer-per mesh

One thing about cantennas is that they are linearly polarised, so you could go from half to full duplex on the same frequency by having four of them, two at either end, rotated 90 degrees apart.