been having this argument with a guy at my club for like two months now. he swears by running max power on his vtx (600mw on a 5.8 setup) with stock antennas and says thats all you need. im on the opposite side, i run 200mw but spent actual money on a pair of lumenier axii antennas on the quad side and a crosshair panel on the ground.

we've done some informal range tests and honestly the results are kind of all over the place depending on the environment. in open fields he gets maybe slightly more distance before breakup but in anything with obstacles or buildings my setup seems to handle multipath way better and the image stays cleaner. i feel like antenna quality and polarization matching is being slept on by a lot of people and everyone just cranks the power thinking that fixes everything

is there any actual data or consensus on this or is it just gonna depend on the specific setup forever

your instinct is right but its not really an either/or thing. higher power helps with line of sight range, better antennas help with everything else ? multipath rejection, pattern coverage, handling reflections. the axii is a circularly polarized antenna which means it rejects a lot of the garbage reflections that linearly polarized stock antennas pick up. so at the same power level you're effectively getting cleaner signal even if the raw rssi number isnt always higher.

the real answer is both matter and you should do both, but if i had to spend money on one first it would always be the antenna. going from a crappy dipole to a decent lhcp setup at the same power level is a bigger real-world improvement than doubling your vtx wattage with bad antennas. also worth noting that 600mw in a lot of countries is technically over the legal limit for fpv use so thats another reason people might want to keep power down and invest in antenna quality instead

honestly the multipath thing is so underrated and nobody talks about it enough. i was getting these horrible horizontal streaks flying near chain link fences and concrete walls and i thought my vtx was dying. swapped to circular polarized on both ends and it basically disappeared. your friend is probably fine in open fields because there's nothing to cause multipath there so cranking power works fine but try his setup in an urban or industrial environment and i bet it falls apart fast