I agree, but be careful I am no expert.
Most of my output is 1080 so the ipad and iphone player can use it.
I am shooting HD 1440 on six gopros that has to then fit into 1920 by 1080.
if the the player shows you the whole image captured by only one gopro, you are seeing 1/6 of what I have compressed into 1080.
The quality is according to this. Don't enlarge the player to more than 1/6 of 1080 frame size, if this makes sense, or you are pixel peeping
What to do?. Option I have been using is to set the player to Little Planet projection, then zoom in to normal perspective, modest player size.
Looks OK for me.
Output at 4000 is great Image Quality but the file size is enormous, no problem if it is on local drive.
If you want to see comparison then some files for you below. Not so good production values yet (if ever but I am learning)
right click and save link as to download
360 video at 1080, 24 Mb, https://s3-us-west-2.amazonaws.com/dofphoto.net/360video/car1920.mp4
360 video at 4000, 90 Mb, https://s3-us-west-2.amazonaws.com/dofphoto.net/360video/car4000.mp4
Flat video of 4000 via Adobe Premiere CC to show zoomed in IQ, 36 Mb, https://s3-us-west-2.amazonaws.com/dofphoto.net/360video/CarCC.mp4