Holy smokes, have you guys seen the Ruckus systems?
I set up the Cisco, Adtran and BlueSocket but we recently got a Ruckus system in as a demo system and set up various AP's in mesh mode around the building.
At 25% power levels the AP's are showing a much stronger signal then any of the others. Very intuitive to set up and rather easy to manage.
The BlueSocket/Adtran is great for having a single controller and multiple AP's at different facilities all remotely managed where data does not have to come all the way back to the controller to be dumped on to the network. They even have a survival mode so if the link to the controller is lost users can still use the local AP's.
Cisco, has the Clean Air technology which is supposed to help mitigate problems by hopping channels. I cannot confirm this because we always like to lock down the channels during you network assessments.
Engenius AP's, pretty inexpensive for Atheros radios. They seem to work better then you would expect for their price great autonomous units.