Hi, on the P3A, which recording format is the best ? 1920@50 or 2704@25 when recording video ?

Depends on what you're trying to achieve. There are professional videographers who really like 25 fps - it apparently produces what many of them think is a pleasing "cinematic" effect.

Take a peek at phantomhelp.com - there's a lot of "how to" information in there and someone may have already addressed exactly what you want to know.

Also, 1080P (1920) will play back on almost any device, once you get into 2.7K and 4K, the playback can get a little tricky.  I recorded my first flight on my P3P in 4K only to find out that NONE of my computers, laptops, tablets or TV's will playback 4K...but 1080P works fine???

I took videos of 1080P 60FPS versus 2. K at 30FPS yesterday, and from what I can tell... just stock footage, no post edit, the color information is greater with 2.7K. The colors pop more. Although I still take 60 FPS with the 1080P Imo.

cool, I was also thinking that the 1080 pic should be more stable/smoother with the 60 fps ?

From what I understand (which is very little) if you record in 2.7k you have more editing "options" as far as cropping goes.  This would be good to keep the main shot you want but crop out any areas where props get in the FOV.  I might try doing some side by side comparisons tomorrow (using the new way point options of course!) as far as video quality between 1080p and 2.7k!

2.7 def has more cropping capabilities. But just like 4k , you need to decide if the extra editing time is worth it.