if saving to computer, wouldn't the video quality be better direct from SD card on Mavic?
If you want the audio, it's with the video that the AC sends to your device. Recall that the audio is produced by the device, not the AC. In my experience, provided I fly at a height of at least 20m or more, the sound of the AC does not overwhelm the ambient sounds on the ground that my iPad's dual microphones pick up. IMO, being able to play the ambient sounds, in addition to whatever music I choose, adds a whole new dimension to the video. I reside in an urban area,so there are always lots of sounds: helicopters flying overhead, autos and other vehicles on the ground, etc. Earlier today, a group of three men decided to have a keg party not far from me in the vacant parking lot, so I got some unusual sounds. If ever it's important for me to hear my own voice clearly, I have a wired double-lavalier device that is designed for interviews. I pin one mic to my collar and allow the other to pick up the ambient sounds.
I always shoot at 1080p/30@1/60 (which another member describes as "the sweet spot" resolution; however, he also states the reason he does not use it). This allows me to select Full HD (1080p) on the HD tab.
In my experience, the video is the same quality as what I get from the memory card on the AC -- plus it has the audio. This may be because I'm careful to watch that the HD signal that I'm receiving is always 5 bars. This is easy for me to achieve because, although I often take my AC to the maximum allowed height (120m) and adjust my RC's antennas accordingly (horizontal to the ground which also results in 5 bars of RC signal), I rarely fly it at a radius that is far from my Home Point. The reason is that I reside in an urban area, and I'm careful never to violate FAA rules. I launch from near-empty parking lots and do not allow my AC to travel beyond the boundaries of the lots.
Apart from following the FAA rules re VLOS, I have an emotional attachment to my Alpine White Mavic Pro. It would be hard for me to forgive myself if ever it came down, and I could not find it. Provided I can find it, I can either repair or replace it with DJI Care/Refresh.
Here is one final reason to prefer the video that ends up on my iPad. When I first got the AC and I was attempting to remove the 16GB card that came with it, my AC ate the card -- instead of popping out after pressing it, the card went inside the AC. True, the $418 bill was covered by the warranty, and DJI even paid the shipping both ways, but I was unable to fly it for a few weeks
So, although KlooGee thinks of the video on his iPhone as his backup, I like to think of the one on my 128GB iPad as my primary. If ever it happens that the quality is for some reason poor, I can always use the one on the AC's removable memory card as my backup while pleading with my AC not to eat it again
EDIT: I just thought of yet another reason to think of the video on my iPad as the preferred edition: although I haven't yet experimented with it, there are a number of videos on YouTube which suggest that one may have a lot of fun using DJI GO 4's Editor to quickly create a finished product that is ready for export to a variety of destinations. (However, some also complain that these creations have the DJI logo on them, which is the reason they don't often use it.)
EDIT: 2018 0422@0948: Re "In my experience, the video is the same quality as what I get from the memory card on the AC" should read "In my experience, the video is the same quality as what I get from the memory card on the AC
when played on a 1080p HDTV."