I need to make a temporary wireless bridge to connect some prefabs with the rest of the school for the next couple of weeks and a month or so next year.

I'm looking at getting a couple of these NanoStation Locos and putting one at each end of the 40m gap. Then using an existing wireless access point so that the teachers at least can access the school's existing network.

http://www.ubnt.com/nanostationloco

Drawbacks? Gotchas that I need to be aware of?