A P2 has a range of over 3Km with the stock Tx/Rx.I have my doubts when someone says they have flown their Phantom beyond 4,000 feet using stock equipment.
Theoretically, that is also the height limit straight over your head.
However, going up is not the challenge. Going down is! With 2m/sec max (I would go for 1.5 max because with 2m/s you still get VRS somewhere on the way down), It would take you between 1500-2500 seconds!!!!
Some people had to shut down the engines and go down in free fall to save juice.
Wouldn't recommend that.
The highest I flew is 500m, using Fatshark FPV with IOSD.
300 is allowed here.
Not much difference in the views with a Gopro, between 300m and 500m, it only takes more then 6 minutes to get down safely, nerve wrecking and totally not worth it.