about new motors
it's true that lower kv will produce less heat and more efficient and the impact is with longer flightime, can use bigger props and less stress to the batts, that is the pro
but how much? that is the questions
con:
1. lower thust produced,
2. with same size props power or throttle needed to take of and hover add more
3. to match same power or throttle needed to take off with higher kv, it will need bigger props with lower kv motors
4. maximum speed will less with lower kv (well since dji limiting the speed, it's no use anyway)
every motors have some pro and cons
it depends on how you fly the quad, higher kv can produce less heat by fly around
if you fly agresively well ofcourse flightime will be sacrificed wheter in high kv or lower kv
and also i dont believe with someone (especially newbie) claimed that this, and that, and what if, what so ever, etc. Since there are so many newbies with P3 and make such a wuss about something
in this case longer flightime? well prove it with a video, picture will tell definetly, no need fly the old ones, just fly the newer motors and count the duration.
i can say this because i have some experience with own assembled 450, 500, 550, 650, 690, 250 quads and hexas with many different KV and size
it's abit what you called experiment