In my experience, it's all about interference.
Out in the country (miles and miles of nothing but flat farm land, not even electricity). I've flown over 3400ft (yes, three thousand four hundred) away (all stock). But fly behind anything (building or even a tree with no leaves on it) and I almost instantly lose connection (at almost any distance.)
At home (in suburb subdivision where every house has wifi, cordless phones, microwaves, ...) I've flown as far as 1000 ft, but most of the time I lose connection by 500 feet.
At a park in my neighborhood (less than 2000 feet from my house) I have gone as far as 1250 feet, but mostly I lose connection as soon as I fly near houses (usually 500 to 700 feet).
All of this with the exact same stock setup.
Go out to the country, where there's nothing but flat open land and fly away sideways (keeping the left side or the right side of the P2V pointing at you) and you will be shocked how far you can fly (well out of visual or audible range.) It is frightening because as soon as you turn the P2V (so that the side is not pointing at you) you will lose video feed and telemetry. I tried to fly back, but after a few minutes I decided to not panic and turned off the controller and it returned home (too cool, but not something to depend on, I did it because I was in the middle of nothing but farm land and it was not possible to hurt anything other than the P2V itself.)
Happy flying.