Andrew Milluzi just posted an in-depth article on using the NXTBee radios with Labview for LEGO MINDSTORMS (LVLM). He gives some great background information on data Throughput, Latency, and Speed.
Check out his blog post here: http://08milluz.wordpress.com/2013/02/20/throughput-latency-and-bus-speed/
You can also find some software on his website for using the NXTBee’s and LVLM. While RS485 communications are not officially supported in Labview for LEGO MINDSTORMS, he has some great downloads that work very well with the NXTBee.