We recently completed a large wireless infrastructure installation project in our area (covers entire county) for fire prevention. We used a lot of Ubiquiti's for short range point to point links. The links are anywhere from building to building, to firestation to firestation; the longest links are a mile to mile and a half. Radios used for long range were from Radwin. We are certified with Firetide, Proxim, and Bridgewave so we are familiar with different types of radios.
The first set of radios went up a year ago and we have not had a single problem with any of the Ubiquit radios.
I do believe Ubiquiti is definitely putting pressure on the wireless companies that make "carrier" grade radios and try to compete in the ISM spectrum market. Engenius is another company with a good set of radios that can be used for point to point applications.
Hal, you tried to mesh them? I didn't think they had mesh routing capability other than maybe setting them up in WDS mode which is really not a true mesh. And if this mode worked with more than two radios, I would think they'd be very slow cause you're using a single radio to relay packets from units that are within the hearing/operating range of the radio.