I'd be very cautious until you've flown several (or more) missions. A lot will depend on gps reception during the flight -- and because I fly in an area with lots of very tall trees, I figure that there's a good chance they will block at least some satellites if I fly below and close to the tree line. I also learned the hard way that adjusting your Phantom's compass to compensate for magnetic declination is vital for holding the quad close to the planned flight path. My current procedure is test fly a mission at 200-250' feet just to make sure there are no unexpected obstacles or detours. I fly FPV, especially watching for tree tops!