I think you nailed the market split between Ubiquiti and Fluidmesh/Firetide. For small installs, UBNT is fine. Simple point to point stuff, no problem. If you have more challenging requirements, you will very quickly understand why you pay more for Fluidmesh or Firetide.
Favorite Wireless Video Surveillance 2014
We surveyed 120 integrators asking them "What, if any, is your favorite wireless system to use with video surveillance? Why?"
5 manufacturers stood out, with 1 interesting rising company who did not make our 2011 ranking.
In this note, we examine whom these manufacturers are and the reasons integrators gave for choosing them.
On an Engenius line, are the wireless dependable and what is the website so we can check out their stuff?
Engenius wireless outdoor product directory
As for reliability, we don't have enough experience to comment but there does seem to be a number of integrators (as shown above) that are satisfied with their reliability and performance.
I am not sure if the support from Firetide makes it an attractive proposition here in the Middle East. We used Firetide Wireless Access Points to create a kind of Hotspot for a Customer in their Passengers facility where 100s of tourists arrive and leave every day. We asked Firetide to create a simple login page to capture guest details such as name, phone number, and email address when a tourist tries to connect to the Internet the first time over the WiFi network through their smartphone, tablet or laptop. This could have been easily done by one of their software engineers based in Bangalore. They decided not do, saying that it is not their business!