Distance varies highly depending on where you are flying. Setting the wifi channel to manual and selecting a channel that has less signal helps. On the bottom of the network setting for freeflight pro will show a graph of wifi channels and how many signals are present. (it takes a few seconds for it to show it)
I have the skyshit2 booster mod installed and in most cases my distance is at least doubled from stock. As an example this is two flights taken from the same location and flying the same direction, one with a stock controller, the other one boosted. I could have flown a bit further but I was concerned about the battery.
Stock was about 1200 meters, Boosters got me 2250 meters.
Mike