the range was b/w 400m - 500m, in clear area, the antenna's facing each other. when hidden behind a building the apc's stopped communicating after 400m approx , there might be a problem with battery voltages, cause i designed the power-supply to work at 8-30v DC, and i had to use 9v batteries when took the PCB outside. and no i didnt try other baud-rates, but the range would be better for 4800,2400 bauds. the air rate was 9600 bauds.
PS. as the distance increased the data rate became slow.