What's the area of the office and what barriers exist between employees? Concrete or internal metal/plaster walls? Other offices / businesses near by where the

What's the area of the office and what barriers exist between employees? Concrete or internal metal/plaster walls? Other offices / businesses near by where the employees pick up the SSID's with full or near full strength? I've found older Apple Airport Extreme's work really well and are easy to setup and manage. I can't personally comment on the current version.