I have been using the Series 2 XBee modules with ZB firmware (v2x41). Their range is greatly dependent on the environment and what is between two units and which antenna is on the module.
With the wire antennas I have a good link from the basement (coordinator) through cider block walls and wood floors to the sunroom (router) about 40 feet away. From there to the garage (end device), 30 feet, is difficult as the garage has foil lined insulation, a metal door and window screens. The link is good if the module inside the garage is placed to avoid this shielding.
The next module (end device) is behind the garage, ~60 feet to the sunroom. Works well if the module is placed so the garage does not block the path otherwise I get a very marginal link. I plan to put a router high in the attic for a better path to the garage and the backyard.
I haven't tried to see what the open line of sight range can be.
Hope this is helpful.